Demon Slayer: Yakuza Rising
by Hyaenodon
Summary: After being killed by Tomura Shigaraki, Overhaul found himself in the universe where his plan of reinstating Yakuza can be fulfilled without using extreme acts like before. However, he also must search new allies and contend with the Demon Slayers and Oni. Rated T because of Overhaul's Quirk. a BnH x KnY x Rurouni Kenshin triple crossover. Enjoy! Beware SPOILERS!
1. Chapter 1:Return Back on Time

**/N: Boku no Hero Academia is written and illustrated by Kouhei Horikoshi. Kimetsu no Yaiba is written and illustrated by Koyoharu Goutoge. Rurouni Kenshin is written and illustrated by Nobuhiro Watsuki. I don't own the three of them.**

* * *

**How to read the story**

In the… – Normal

"You're…" – Conversation

'Why…' – Thought and telepathic communication

Kagune – Foreign words

"**Fired…"** – Deep Voice

**Tetsusaiga** – Technique, Quirk and special weapons

* * *

**Chapter 1**

**Return Back on Time**

"Who's the one that said "I'm going to be the next leader" huh?"

"Did you come here to kill me?" Ask the once notorious villain known as Overhaul, or his real name is Kai Chisaki toward the current leader of League of Villains, Tomura Shigaraki.

Thanks to the Raid of his base, Shie Hassaikai, the last known Yakuza that still operated in Japan during the Age of Heroes by the combined forces of Police and Pro-heroes. It was all crumbled.

His dreams of reinstating Yakuza as the underworld super power once more through his **Quirk-destroying Bullets**.

His plans of eradicating Quirks from existence.

His dreams to becoming the next ruler of the night (villain) after the imprisonment of the most notorious villain of Japan, All for One.

But the most important of all, his dream to paid the debt to his boss who kindly takes him as a boy.

Now, all of that dreams is lost. He himself even lose to first-year U.A Academy student who unexpectedly outclass him in every way even after he fused with his underlings who had the ability to absorb the opponent's life force.

He's the same as a man who already give up on everything.

"Well yes." Tomura replied. "Actually I plan to make you suffer by cutting off your arm thus make you Quirk-less so you can watch helplessly from prison. However… I change my mind suddenly. Let me be blunt now… I hate your guts. Because you act so high and mighty."

Suddenly, Mr. Compress, one of Tomura's comrades is compressing a part of Kai's left arm using his Quirk, **Compression**. "I also feel the same." He said, agreeing with Tomura's statement.

Tomura then hold two small box on his hands which one of the boxes filled with four complete **Quirk-destroying Bullets**. One of them is already used to make Mirio Togata, one of the Big 3 from U.A become Quirk-less. "Two small box. Which one is the complete product?" He asked Kai before putting it into his pocket. "Well, not that I care."

Kai suddenly had the drive after seeing his hard-work for years is easily stolen like that. "Give it back!" He demanded.

"After all Overhaul-" Tomura later released his mask, which is someone's hand-palm. "-Someone who wants to extinguish Quirks from society… Doesn't need a Quirk right?" Tomura later grip Kai's remaining arm, starting to disintegrate it due to the power of his Quirk, **Decay**.

Kai face is showing shock, anger, and fear. He knows that's nothing he can do.

This is the end of the road for him.

"Sad isn't it?" Tomura looks toward Kai with a sick smile on his face. "All of your hard work till' now… IT'S ALL MINE NOW! YOU CAN WATCH US FROM HELL ALL YOU LIKE! I HOPE YOU HAVE A NICE TRIP TO THE AFTERLIFE!?" He yelled toward Overhaul body, who starting to disintegrate.

Overhaul only experience a state of shock and fear as the disintegration started to decaying his body.

'This is what I get!? No! I-' His thought never finished as his body finally decaying.

From the truck that used by Shigaraki and Mr. Compress, Spinner called. "Oi! Come quick! The police will arrive soon!" He warned.

Agreed with his comrades, Tomura along with Mr. Compress and Dabi is walking back toward their truck, leaving the decaying corpse of Shie Hassaikai's young master behind.

"Next… It's our time." Tomura declared with firm tone.

* * *

For Kai, he's now feel like he was in Limbo.

All of his hard-work, truly fails.

It is so wrong to want to repay your debt to someone? That's the thought that accompany him on this limbo.

'Grrh… Damn those heroes! League of Villains! They're just a bunch of sickos who view small true thing in front of them. Never look the bigger picture!' He thought the same thought when he was defeated by Izuku Midoriya. 'If only Quirk never existed! Pops would never have a sad look on his face! Damn you fake heroes! If only I can return to the time where Yakuza can go strong once more-'

"Khu khu khu."

'Someone's chuckling!' Kai thought. How's it possible? Isn't he dead by now?

"This human surely will be tasteful. It's been a while since I eat a muscular man like this." The voice of a man said in vile tone. It was revealed to be a malevolent being of a man with pale skin and a horn on his head. He then picks up Kai's left arm which developing hives on it. "Well then. Time to eat!" He said as he going to take a bite.

However, Kai's mysophobia reflectively makes Kai use his right arm to grip the malevolent being. "DON'T TOUCH ME!" Kai shouted in anger as he instantly activated his **Overhaul** on the being. The being can only look in shock as his face and every parts of his upper body starting to show veins before it become inflate and his upper body explodes completely, leaving shower of blood behind that some of it rain down to Kai's body.

Kai later got up and starting to clean the blood from his body due to his mysophobia. It is revealed that he's lying on a ground of what seems to be a forest edge. The lower half of the malevolent being that tried to eat him is seen lied motionless beside him.

'Now then…. Where am I exactly? Am I supposed to be dead?' He looks his surrounding after he finishes cleaning the filth from his body and found out that he wear his trademark plague mask. "Judging from the fresh air, seemingly I'm in the forest of Japan or something… Huh?" He then looks at the being who tried to attacking him. 'Who or what is that man? He said he tried to eat me? Maybe he had Quirk like Tabe?' He thought remembering one of his Eight Expendable Bullets. "Well, at least he won't bother me." He then walk away from the scene, tried to find out where he is exactly.

* * *

To say Kai was confused is beyond that. He's clearly shocked by what he seen.

Recently after walk away from the forest, he discovers a town, or village to be precise. He's clearly shocked by its lack of technology and the clothing of its people that seems very backward.

Heck, even asphalt path and concrete rock hardly exists.

'What's the meaning of this?' Kai thought in confusion. The air, the scenery, all seems backward. But, the existence of electric pole to light up the house means one thing…

'Could this probably…. Japan around early 20th Century?' Kai's mind quickly deduced. He finally remembers it due to his Pops tells him about the time when the Hero started appearing and pushes Yakuza to the shadows. 'That's impossible isn't it? Is it possibly that I being thrown to this backward world? That means this time… Just a few years before the sickness of heroes and villainy is born?'

However, he soon draw the attention of the villagers.

"Look at that man."

"Who's he exactly?"

"His clothing seems strange to me."

"What's with that strange mask?"

'Ugh… This sick people.' Kai thought in frustration. However, he already push his mysophobia and killing intent for now to appear civil enough not cause mayhem.

'For now, I think the best option is to find a library in this small village.' He thought before walking toward a random female villagers. "Excuse me Ms, can you show me the way to the library?" He asked in kind tone.

The female at first is scared because of Kai's menacing mask, but finally agreed and escort him to the closest script building. "Y-yes. It is that way. I'll escort you!"

"Thank you very much." Kai thanked while making his facade smile that of course unseen because of his plague mask.

* * *

Kai later is escort to the closest script building that's available on this village-like city. In there, the first thing that he takes is about the history of Japan. He then reading the scroll for an hour, before he widens his eyes. 'This is….'

He really found something interesting. There's no telling about Quirk at all. What tells on the history is all about the history of Japan and there's nothing about those vile sickness. Heck, even no records about All for One. But there are two history records that interest him. The first record is about Yakuza. Seemingly on this era known as Taisho, Yakuza is a collection of numerous thugs with brotherly bond that mainly an outcasts, not really different from his time. Except on this time, they're still able to grow without the intervention of heroes. Even he reads that some Yakuza is humanist enough to help civilians that reside on the district that they rule.

But it's the second thing that seemingly picks his interest.

The myth about Oni. It is told in the script that every night, the malevolent creatures known as Oni will kill and eat any unsuspecting humans who wander alone. It is said from the script that they become flourished or more exactly recorded after Sengoku Period.

"Well… That was interesting enough." Kai commented to the content. "So in this era, there no such thing as hero sickness, so Yakuza can thrive. Pops principle really fit for this period." Kai mused to himself remembering his Pops principle about the old tradition of Yakuza. If Yakuza in here still thriving although with surveillance from the government, he doesn't need to use that vile plan. Using the old tradition method is more than enough. "But at the same time, this Oni picks my interest. So in other words, their leader is the master of the night. And that left me wonder, who's the master of the day? What kind of heroes' sickness in here?" He mused to himself.

"Oh, I see that the script of history is occupied." Kai then look up from his reading to see a young woman that's maybe around Mirio's age. She had pale skin and long, straight hair of a very dark gray color that reached just below her waist, worn down with two shorter clumps over her shoulders, and arched, ear-length bangs on either side of her face. Her eyes were a pale violet and slanted towards the sides of her face, bright and bug-like, with many notable white sparkles reflecting light off of them. Her body is very slender but Kai's notice that behind this slender body, she's a fighter. "No need to worry Mr. You can read it while I search for something else." She said in a very kind tone.

"No. I already finished reading it." Kai replied as he put the script on the table. "By the way, from what Yakuza's group are you?" He asked since he clearly interest in this woman's outfit. A black uniform with a butterfly wing-pattern haori and a katana on her waist. Truly fit a Yakuza.

"No need to worry Mr, I'm not Yakuza." She assured. "I'm just a passerby on this village that wants to go to the script building. However, that's strange mask you wear there." She commented about Kai's plague mask.

"No need to worry about my mask. I'm just a little sensitive about the dust you see." Kai replied with a fake smile, unseen because of his mask. 'Truly, what a de javu. Someone's asking the same question as you, Lemillion.' He thought.

'This man. I don't know why…. But I feel the strange thing about him.' The young woman thought in confusion. She then closes her eyes, smiled. "I see. Sorry for asking something personal. By the way my name's Kanae Kocho."

"It's okay Ms. Kocho, now if you excuse me." Kai then stand up from his seat, walk out from the building.

As he walks out from the building, he finds another woman waiting on the outside. Kai quickly suspects that she's must be the woman's younger sister due to their almost similar appearance. She was a petite girl with pale skin and large compound-looking eyes that do not possess pupils, only a haze of gradient, purple iris that becomes darker, the lower it goes, which made her eyes appear similar to those of bugs. She had chin-length hair that faded from black into dark purple, that usually were tucked in,. Her outfits is the same as Kanae with darker shade, except she only wear a white haori and also carrying a katana on her waist, although being unseen by a fabric that wraps it.

'Not that I care.' Kai thought as he walks away from the scene. 'But that means… In this world, I can truly become the supreme ruler of the night. The only thing to do now I how will I search some valuable underling since this world had no Quirks and how to get rid of this Oni leader to fulfill my plan?'

* * *

The time later changes from noon to almost sunrise. Kai is spent his time reading about battle techniques script that he stole from the building on one of the house roof of the village. After the matter of dealing with Shigaraki, Kai finally had enough time to think and realized some of his flaws. His mysophobia is unavoidable, but the other is his biggest mistake.

The first is his overconfidence. Due to his overconfidence that his previous plans using Eri will be effective, he failed miserably. From now on, even though he has a plan, he seems must built it very carefully and keeps the key of the plan in hiding.

The second is his underlings' trust. While true maybe his Eight Expendable Bullets is extremely loyal to him except for few person, his brother-in-arms who's more like to follow Pops teaching never saw him as leader but more as an usurper. It also because of his lack of care for his underlings that make two useful pawns from the League of Villains, Toga Himiko and Twice, betray him. Maybe if he not killed that magnet bastard who attacking him, the League of Villains will view him as allies and he'll become the next ruler. The acts of Tomura proves that he cares deeply for his comrades of villains.

"But not what I wanted if it became like that." He once again mused to himself. He read this script for one purpose: practice the moves to improve his fighting style that too over-relied to his Quirk.

Suddenly, Kai's sees a building not far from the place he's sitting is emitting a dust. Clearly there are some battles going on.

Could it be one of Yakuza's gang from this age? Surely they so full of spirit isn't they?

Curious enough, he jump down from the house, while momentarily looking inside the house. "Thanks for the seat." He said as he walks away, revealing that he kills the owner of the houses using his **Overhaul**. His lower body is the one that only remains, while a splatter of blood is seen on the floor.

* * *

Kai later walked toward the sites of carnage, hand on his pocket. He clearly interested in the scene that currently unfold. He then sees the sky and it already showing sunrise.

"Tch, never thought I wasted my time for so long." He uttered, probably because what he usually do during night is experimenting on Eri's DNA to create his **Quirk-destroying Bullets**. However, he then stop walking after seeing someone in front of him.

It was Kanae Kocho, the girl that he encountered on the script library yesterday. She appears to hold her chest, which is revealed to have a huge slash attack that seemingly scratched her heart and damaging her right lung. She support her body using her katana.

"You…" Kanae raspily said, recognizing Kai before falling down face first to the ground because of her injuries.

Kai sighed, before walking with no care passing the dying Kanae. However, a thought suddenly crossed on his mind. 'Maybe this woman can be useful to me for the information that I desired. After all, I can deduced that this woman maybe a samurai or some kind of that, meaning that she's lying for not being a Yakuza.' His head already filled with what use he had for Kanae Kocho. He then turn to the body of Kanae, who continuing to bleed from the wounds. "Don't make me regret touching your filthy body." He said as he prepared to turn Kanae body to heal her body from her injuries. However, just as he's about to touches the body of Kanae…

"B-big sister!" Kai turned to see the same woman that he encountered on the script building entrance. She looks panting, maybe because of running from somewhere else. Her face also shown panic. "Y-you!" She readying her hands on her katana. 'So this man is the one that Big Sister talking about! A man with strange clothing, wearing white gloves, and a strange bird beak-like mask!'

Kai at first tried to use his kind-facade nature. "No need to worry little girl. I just suddenly pass by and found her badly injured. If you want, I can treat her."

"I-is that true!?" The girl clearly panicked but at the same time had a hopeful tone. "Please help my sister!"

"Well not here." He then stand up and walk toward the girl. "At least, I can't risk any witnesses." He then unleashes his killing intent, making the girl wary.

"After all-" Kai later touches the girl head at a speed that surpasses Rappa speed, one of his Eight Expendable Bullets that had a fist that as fast as bullets from gun. He then disassembles some part of her head to cause unconsciousness with extremely fast timing. "-If I'm not keeping you alive, I cannot talk properly with the subject that I desire."

* * *

On the place that seemingly a collections of rooms of tatami that located randomly.

"Is that true what you said, Douma?" Ask a man with red-blood eyes. His physical appearance is like that of a man in his late twenties with an unnaturally pale skin which can be easily confused as being unhealthy and sickly, curly black hair. He also wears a white fedora with a red ribbon and a somewhat extravagant outfit.

"Well in a reality. Then yes!" The rainbow-eyed man known as Doma said. Doma took the form of a young man with a moderately toned and muscular body, who is of a notably pale complexion and possessed unusually long, pointed nails that appeared to be stained a pale blue. His hair could appear either silver or a pale golden blond, and he wore it parted to his left, the shorter parts around his face seeming to flare out to either side around his head, curving backwards with one strand left down his face to fall between his eyes, while the longer parts were left to drape centrally down his back in a thinning spiral. His eyes are rainbow in color. His outfit consists of a blood-red turtleneck of a design that made it appear that the section between his neck and upper chest is covered by a black substance that looks like it's dripping slightly down his body, this same design repeated at his wrists and down his hands. Below this, he wore a pair of straight, tan-colored pants of a pinstriped design, their cuffs visibly loose, which he secured with a pale green-tinged golden belt, its buckle a bright silver. His trademark, Doma is also wearing a black, crown-like hat which is lined with gold around its frontal plates and has flowing black ribbons dangling from each of its sides."During that night before I battling the current Flower Pillar, I found a minor Oni that only its lower half that remains. And when I touch it, It was revealed already dead. Seemingly his core is destroyed." He informed.

Kibutsuji Muzan clearly not expecting this. Not that he cared about the death of his expendable minions, but the description of how this minor Oni death is what that disturbing him. What kind of being that able to target an Oni's core that only as small as gravel? Maybe Demon Slayers can because of their **Nichirin**** Blade** that specifically targeting their neck. But, this kind of attack is something he had never heard of from his almost thousand years old lifespan.

But once again, the one that equalize himself as an almost perfect being and natural disaster dismissed the possibility of threats. The only known person who he considered as his greatest fear is only one.

"Are you sure about this information Douma?" He asked his Upper Moon Two with a little threatening tone. He hated if this information is merely a ruse.

"Pretty sure!" Doma said in his carefree tone.

He then think about it for a while, before spreading his thoughts into his underling.

Investigate this mysterious case. The one that manages to find it will be allowed to Enter the Twelve Demon Moons. For Lower Moons, they can challenge the Upper Moon.

He'll sure will caught this mysterious person who dares to challenge his supremacy as the Ruler of the Night.

* * *

Back to the street, Kai finally turn Kanaes' body to make her back face the ground, exposing her grievous injuries. But, the fact she's still breathing is amazed him.

'She's still alive after a wound like that! Once again a de javu.' Kai thought as he using his **Overhaul** on Kanae body. In slow process, The front of Kanae's upper body is destroyed or exploding into a splatter of blood before magically reassemble itself and after all of that is finished, her fatal injuries is all but gone. Such is the power of **Overhaul**, a Quirk that gain the Wakagashira of Shie Hassaikai a complete control over matter. However, Kai have only one thought in mind after that.

"Tch. Disgusting." He said as he clean his arm from contamination. After finishing cleaning the so-called contamination from his arm, he then look toward the unconscious body of the two females.

**Notes:**

**That's for chapter 1! What do you think so far?**

**By the way, this story take places two years before the massacre of Kamado family.**

**As the Idea of Oni's core, I get the reference from UM 6: Gyuutaro and Daki. Since they said they can separate their cores to avoid death by decapitation, I think all Oni had a core on some places in their body. If the core is destroyed, they as good as dead.**

**Also I want to ask the opinion of reader. How would Overhaul fare against Oni and Demon Slayers? Did you think Muzan and Overhaul personality is the same?**


	2. Chapter 2:Unlikely First Ally

**/N: Boku no Hero Academia is written and illustrated by Kouhei Horikoshi. Kimetsu no Yaiba is written and illustrated by Koyoharu Goutoge. Rurouni Kenshin is written and illustrated by Nobuhiro Watsuki. I don't own the three of them.**

* * *

**How to read the story**

In the… – Normal

"You're…" – Conversation

'Why…' – Thought and telepathic communication

Kagune – Foreign words

"**Fired…"** – Deep Voice

**Tetsusaiga** – Technique, Quirk and special weapons

* * *

**Chapter 2**

**Unlikely First Ally**

At the house where he killed the owner, Kai is carrying both unconscious Kanae and her younger sister to the house. After putting them on the floor, the first thing that he does is cleaning so-called contamination from his clothes.

"Grrgh. The blood." Kai grunted as he rubbed his clothes using his hand from the blood that still stain the clothes of Kanae. "I don't know why, but I got hero vibes by carrying these two."

For their katana, of course Kai's disassemble the one that belongs to Kanae using his Quirk before he bring the siblings here so there's no chance for them to fight back. However, he also anticipated if somehow both of them can do hand to hand combat as well.

However, Kanae younger sister katana picks his interest. It was shaped like a fencing sword but more maximize for strong stabbing. He takes his time to examine it and found out that the katana handle contain some kind of liquid that smells like a flower. He then decided to keep the thing for the time being.

"Still, it's really unthinkable for these two sisters to be a Yakuza." Kai commented at their strange clothing, some kind of uniform with a kanji written "flower" in case of Kanae. This make everything is got more confusing. "Did the age on this time- no, this universe is so low that woman become Yakuza…" He didn't know what his Pops will think about this. Suddenly, he remembers what Pops said to him once.

"I know you're just trying to repay my kindness. However, don't ever turn from the path that I've teach you."

"Pops… Seems on this era, your ways of doing things can be come true." Kai said to himself. "This time I promised. I'll make the strongest Yakuza group on this Era that even the government will afraid against without wavering from your way of teaching. This is the way I redeemed for turning from the path that you teach me." He determined. His death at the hands of Tomura makes him realize how low he fall to evil and disappointed his Pops. Heck, there's no way he can heal his Pops from his comatose that he himself cause using his Quirk. At least, he will honor his teachings in here.

Now, his first job is to find valuable underlings to replace the one that serve him in Shie Hassaikai. Maybe some of this Oni is civilized enough for him to be his groups of Yakuza. After all, having members of Supernatural Beings is going to make his Yakuza's group invincible.

But he does still not know much about Oni. Partially because in his world, those are pure myth and the true thing is Quirk. While in here, the Quirk seemingly not existed or maybe rare.

But somehow, he felt that these two girls also had 'hero sickness' like in his world even though he suspects them to be a part of Yakuza syndicate.

'Well the first thing is to lay low for the time being. But before that, The first thing to do is search some new comrades and-'His thought stopped as he heard the groaning sound of one of his 'captive'.

Groaned, Kanae Kocho finally awake after being unconscious for more than two hours. Kai noted that is because of her fatal injuries that caused it.

"Uuh…" She groaned while touch her forehead. "Where… Is this?" She said in confusion before looking to another sleeping form beside her.

"Shinobu…" Kanae said in relief seeing her dear younger sister is okay without any visible injuries. Seemingly she didn't engage the Upper Moon Oni that she encountered last night.

Suddenly, she realized something and reflectively touching her chest using her right hand. She then widens her eyes in disbelief. 'My wounds… It should be fatal that not even Medic can heal it. But… How'd it suddenly disappear?' She thought in confusion. She then patting her younger sister. "Shinobu… Wake up…"

"Umm… Five minutes more…." The other girl that known as Shinobu uttered as she asleep.

Kanae sighed. She's glad at least her younger sister is okay by replying her words.

"So you're awake huh?" Kai asked as he approached them. "You're awake longer than I expected." He commented as he approached Kanae.

"You… The man from that time…" Kanae realized although she already know about it when he met with her during her injured state. "Where… Is this exactly?" She asked.

Kai decided its time not to use his facade future. He need to make sure to Kanae that he meant business. "Why don't you ask to the person in front of you?" He casually replied.

"Huh?" Kanae later look in front of her and there lay the lower half of the house owner that Kai's killed yesterday. Although she already used to see Oni devouring a human in front of her, she puts a hand on her mouth to hold puke. "Uuuuuhgggghh…."

"A swordsman can't hold seeing something like this? How sad." Kai commented with casual tone.

Seeing shocked for a while, Kanae later look at Kai with narrowed eyes. "You… You did this?" She asked in a low tone.

"And what if I did?" Kai asked. "I just pass by and because I'm tired, I want to sleep in his house for night, but he just do too much talk. And that's annoying me. I really don't like people excuse you see." Kai explained his reason, showing his nature as villain Overhaul.

"But you're also human!" Kanae reasoned. "Why did you do something like this to the innocent!?" She yelled before coughing, maybe because she's not fully healed yet.

Kai sighed, getting tired of this women reason. "As I suspect this world also sick because of 'hero sickness'. But, maybe not as potent as my world." He commented. "You never saw a human do something like this am I right? I can bet before somehow you hold that katana, you life in a very happy family." He said with a little sadness, remembering the Pops. "However… If that's the case, your katana is just a decoration huh? What kind of swordsman are you if they can't ready to kill a human being?" Kai commented rudely.

"Why…" Kanae tried to get up, however she suddenly falls. "Ugh… Why I can't feel my legs?"

"I destroyed the joints in you and your sister legs when both of you are unconscious. Now you won't be able to stand freely or get out from where. I already close the entire route of escaping." Kai said. Revealed that on the outside, several stone spikes is formed by his Quirk to block any means of escaping. "Oh and for you katana, I've destroyed it. There's no way you can defend yourself now."

"Y-you monster." She stated. This man clearly is such a genius man, able to predict every outcome that'll happen if she's unconscious.

"Well, humanity always had monster hidden in them." Kai later sit close to her. "Both good and bad. But… Their monster is appears in one form usually: hatred. Just like you feel now. No matter how kind you are, once angry, a monster is finally come out from your body."

Kanae then look down, unable to reply Kai's comment at all. Surely something has happened to him to make his view of life almost like an Oni that she usually killed. She then decided to ask. "Are you… an Oni?" She asked firmly.

"If I am, both of you won't be alive now." Kai stated. "Of course I'm plain human. After all, lives that only able to eat human flesh, immortal, and focused on one drive is boring."

"Then, why'd you ask about Yakuza at that time?" Kanae asked.

"I'm Yakuza." Kai simply replied. "Are you not as well?"

Kanae narrowed her eyes. "I'm not a part of a murderous group of thugs like that. What they do is just make innocent wary."

Reflectively, Kai use his right hand to choke Kanae very hard. The force is so strong that even make the accomplished **Breath of Flower** gasp for air. However, he hold himself from using his Quirk.

"Kggh…Aaggh…" Kanae grunted, trying to free herself from Kai choking. But her condition that still recently healed makes her body unable to utilize her usual strength.

Kai look down, a dark shade shadowed his eyes. "You say what just now?" He asked while unleashing his killing intent. He later looks at her with his eyes expressing fury. "Don't you dare treat Yakuza as villains that has no heart." He said menacingly.

However at the same time, Shinobu finally awake from her sleep, having her disassembled part of her head already by Kai previously. She then sit up and rub her eyes. "Big sister, did you the one that-" She later shocked to see Kai choking her big sister and see that Kanae are starting to gasp for air.

Shinobu widen her eyes. Her first action is launch toward Kai and grip the hand that choke her sister. "Let go of my sister!" She yelled with hatred look on her eyes.

However, this makes Kai become furious because of his mysophobia. "Don't touch me!" Kai later use his other hand to choke Shinobu as well. However, different than Kanae, he using his **Overhaul** on Shinobu's throat, destroying the front part of her neck which is unseen because of the choke actions, making some bloods drips on Kai's hand, before reassemble it again with a narrowed trachea. During the entire process, Shinobu is screaming in pain. After it is finish, he later drops the younger sister of Kanae to the floor. The latter just curling shakily on the ground while grabbing her neck because of asphyxia.

Kanae look at her sister with a worried expression despite the pain of being choked. "Sh…Shino…bu…" She rapidly said.

Kai's grip on her is still strong. How like he want to do the same thing to her like he did to her younger sister for badmouthing the organization that raise him if she didn't serve as a perfect informant for him. However, his eyes later softened a bit after seeing what's in front of her.

Kanae Kocho is seen crying. A single tear is rolling down her cheek.

"P…Pl…ease….You….can….do….anything….with…me…but…please….don't hurt….my…sister." She said hardly while crying. "Please..."

Seeing the scene making Kai seems had a little pity. He starting to remembering his Pops once more. "So both of you already lost your parents huh?" Kai asked before releasing Kanae from his choke, making her fall butt first to the floor. Kanae later breathing hard after being freed from Kai clutches. Kai later approached Shinobu who's still choking her neck from asphyxia. "Get your hand off from your neck." He said but since she didn't respond, Kai then forcefully swat her hands and grip her neck while using his **Overhaul**.

"Wh-what are you doing!?" Kanae clearly shocked by what Kai's actions.

"Just silence." Kai replied in annoyed tone as the same process as before happened. Shinobu this time gurgled in pain because lack of air. After the process is finished, Shinobu's trachea already return to normal. The latter is immediately gasps for air.

"Shinobu!" Kanae yelled in relief as she crawled to her sister due to **Overhaul** destroyed the joint on her legs. She later hug her sister. "Shinobu!" She later cried.

Shinobu coughed for a moment. "B-big sister…" She later return the hug, crying as well. "I-I'm so glad you're okay!" She cried. "I-I thought you're-" She unable to continue as she cried harder.

"It's okay Shinobu. It's okay… I'm here." Kanae assured her sister as she softly patting her head.

Kai see the siblings in a little sympathy while he sit on the floor. Both of them only have each other, their circumstances is still better than him. "It must be good still having siblings that care for you…" He uttered.

Kanae then look at Kai after wiping her tears. "Th-thank you! For what you did! Thanks for hearing my request!" She said in gratitude.

"Don't thank me." Kai replied. "Thank that I still have enough sympathy for you."

"But still, I thank you as well for healing my injuries." Kanae said. "I know that deep down, you're a kind person."

"I'm not." Kai denied. "And besides, do you think I helped you is out of kindness?"

This make Shinobu tensed. "What do you mean? What did you did to my sister!?"

"I did nothing other than repairing her injuries and destroy her katana." Kai simply replied. "And also to prevent your escaping, I disassembled the joint bone in your leg."

Shinobu about to get angry at him when Kanae pat her shoulder. "Big sister?"

"Don't worry Shinobu." Kanae assured with a smile before look toward Kai seriously. "Besides, he's saving us. I somehow will tried to negotiate with him."

"Is that so? You really think I'll let you go easily?" Kai asked. "What I want is simple: I want to know what Oni is and what are Yakuza girl like you doing in a small village like this? Which syndicate are you?"

"And if I told you, will you set me and my sister free?" Kanae asked with a serious tone.

"Depends." Kai replied.

"Why you-"

"Shinobu." Kanae said to her sister. "Both of us is weaponless and not in condition to fight. Let just answer his question first." She advised.

Shinobu is confused with her sister words, before huffed. "Fine, Big Sister."

Kanae smiled that Shinobu is agreed. She then look toward Kai. "Okay then, what question that I shall answer first?"

"You're free." Kai replied.

"Fine then. The minor question first." Kanae take a deep breath first. "The first thing that we want to say is… Both I and Shinobu are not a Yakuza. I'm sorry again for saying this… But we're better than criminal like them." She honestly replied.

"I see." Kai commented. "If that so, what reason do you had a katana? I've read the history script that time, it tell that after Meiji Restoration was a success, everyone in Japan is prohibited of bringing sword or weapons of any kind. If exposed, you'll be imprisoned." Kai stated what he read yesterday. "If that so… You're some kind of ronin as well?"

"We're not ronin." Shinobu now speak up. "Don't compare us to criminal like them and Yakuza."

"Shinobu." Kanae warned her younger sister brash words. "Sorry for my younger sister. She's really brash and blunt about her words and actions you see."

"Fine with me. If so… She can be a great Yakuza young master." Kai complimented.

Shinobu grit her teeth in anger.

"For the first question. The answer is connected to your question about Oni." Kanae said. "Now for what Oni is… It will take a long time to explain. Are you okay with that?" She asked.

"It's okay. I have enough time to hear it." Kai assured her. "You can begin."

Kanae nodded. "Oni… If you read legends, it say that they was malevolent being right? Well Oni due exists. Although not like the legend said."

"What do you mean by that?" Kai asked curiously.

"Oni is true monster. Malevolent beings that on his mind only eat to increase their strength. They came in variety of forms. The more humans they eat the stronger they gets. They're also immortal and eternally young." She explained.

"I bet there's more than that huh?" Kai guessed. "But I think the term immortal is too exaggerated. There's no one is immortal besides the God."

"You maybe right. But hard truth is... The Oni… Is used to be human. All of them is created by one man: Muzan Kibutsuji. The first Oni that ever existed." Kanae revealed with a little hatred on her tone when she said Muzan's name. "They retain their human personality. But it often turns into a twisted version of their real personality." She said.

Kai however not surprised at all. All for One is known to making Nomu, monster that was originally human. It's a natural to him. But still, this Muzan Kibutsuji must be this world version of All for One, although he doubt that Muzan is more powerful than All for One.

Kanae caught Kai usual expression. "You're not surprised at all?"

"No. It's already common enough for me." Kai replied. "You can continue."

"Oni is very durable. They have extreme regeneration of their body and able to adapt at any environment. And some Oni had supernatural abilities called **Blood Demon Arts**. Each Oni had a different attributes of these." Kanae explaining Oni's ability.

'Each have specific attributes huh? Much like Quirk then.' Kai literally keep this important information in mind. Each had different attributes meaning that each user of **Blood Demon Arts** have their advantages also their weakness. "If Oni really that formidable, how to fight them?" He asked the most important thing of all.

"There are known three ways to battle an Oni on equal terms." Kanae said while raising her right index, middle, and ring finger. "First, although had extreme regeneration, Oni is vulnerable to sunlight."

'Not useful. Instinctively they already known.' Kai thought. He'll keep this first weakness though.

"The second is **Nichirin Katana**. They are blades made out of Scarlet Crimson Iron Sand and Scarlet Crimson Ore, which absorbed sunlight to such an extent that a decapitation strike with such a weapon can instantly kill an Oni. My katana that you destroyed and Shinobu both are **Nichirin Katana**." Kanae explain the second weakness.

"But why must neck? You say that this katana is absorbing sunlight." Kai asked while holding Shinobu katana.

"Because the neck is Oni's vital part. Other that attacking the neck or destroying the head, they've just regenerates. And usual katana or other weapons can't kill an Oni even if you managed to decapitate them." Shinobu take over the explanation.

"What about nuclear?"

"Nuclear? What's that?" Kanae ask in confusion.

"Forget it." Kai dismissed. 'So in this era, nuclear concept still an alien thing huh?' He put that in mind. Every advanced modern weapon not known enough, although he knows that cruiser ship already existed. "Then… Can all sword-smith make this **Nichirin katana**?"

Kanae later look down. "Sorry. But my organization will never reveal the location to the outsiders." She uttered.

"I see." Kai sighed. "Then, the last weakness is what?"

"Let me explain this Big Sister." Shinobu said.

"Okay then." Kanae agreed.

"Well the last weakness is Wisteria. So please put it into that head of yours." Shinobu said.

"Shinobu!" Kanae worried because of her sister attitude. She knew that Kai can attack them if they not cooperate enough.

Kai, however seems not mind. In fact, Shinobu attitude amused him. "Wisteria? Is that some kind of flower?"

"Your thick head is quick to think then." Shinobu commented. "Well yes. They're a type of flowers that have a scent that Oni didn't like. Given it rights, its nectar mixtures also poisonous to Oni."

Kai later brandishing Shinobu katana. "So… I take it that this **Nichirin katana** is poisonous one huh? Like I said, you're fit for a Yakuza."

Shinobu clearly never expected that Kai able to pieces the puzzle so quickly. "Didn't I already said don't compare me to them?"

"Then the last part." Kai said while sheathing Shinobu **Nichirin katana** back to its scabbard, completely ignoring Shinobu protest. "When explaining Oni, you mention that both of you belong to organization. What kind? This is the last question that I make." Kai stated.

"Well…" Shinobu is confused whether or not to tell their organization toward civilian Yakuza like Kai.

"Well… we're belong to Demon Slayers Corps." Kanae replied.

"Big sister!" Shinobu shouted.

"Although it's forbidden for civilian, seems you deserved to know after the explanation about Oni." Kanae stated, ignoring her younger sister. "Our organization is existed since ancient times with the sole purpose of purging Japan from Oni and protected the humanity from them. We're numbered hundreds but we'd prefer not affiliated with the government."

However, after hearing it, Kai's body is shaking, much like during his fight against Lemillion. 'So that's it!' He thought. 'So that's the 'hero sickness' of this world!'

Kanae become worried of his attitude. "Um… Are you okay?" She asked.

'Why's he shaking like that?!' Shinobu however thought in worry.

Kai shaking however is disappeared after he managed to hold his composure. "If your organization really want you to be hero so much…Why didn't want to be recognized by the government?" He asked with a little venom on his tone.

"Well after that explanation, you know that Oni is stronger than human right? If we're been recognized by the government, I think they'll just got in the way. Besides… Our motto is to prevent any people from suffering the same fate as we did." Kanae reasoned.

"So… Even here 'hero sickness' also existed huh…" Kai commented, although the hero sickness word is not heard by Kanae and Shinobu. "But that means you're more like a vigilantes then?"

Kanae nod. "But we Demon Slayers hadn't minded even if our name never engraved in history. If we can save innocent lives from the shadow… That's enough for us." She said with pride.

"I see." Kai seems satisfied. "Thanks for your consideration to answering my question." He replied. "As gratitude. I'll reveal a little about me."

The sisters later paid attention, intense to knowing this mysterious man with strange mask on his mouth.

"My name is Kai Chisaki." Kai introduced himself. "And like you suspect, I'm Yakuza. Nice to meet you."

"Then, Can I call you Kai then?" Kanae asked. "Your name's really good for a Yakuza."

"Call me anything you like." Kai simply said. "Kanae Kocho and Shinobu Kocho then." He then stand up and walk toward them. "Now please show both of your legs toward me."

Kanae without hesitation, show her feet toward Kai, Shinobu later also do the same. Kai later grip both of their legs. "This is going to be painful." Kai warned.

"Huh?"

True to the warning, Kai destroyed both sisters legs using his Overhaul, making a splatter of blood is sprayed from their feet.

Shinobu is once again screaming in pain, while Kanae did her best to hold the pain. Meanwhile, the feet later magically reform itself until finally, a complete healthy legs along with their socks and shoes is formed.

"Well it's finished, tried to stand up now." Kai said as he finishing the treatments.

Kanae later stand up, and find out that she can. Shinobu then also do the same. "I can stand up again…" Kanae uttered. "Was you a doctor or some kind of that? What kind of ability is that?"

"But... It so painful when the process..." Shinobu uttered.

"Call me a doctor if you feel comfortable." Kai replied. "That ability of mine is something that gifted since I was born. That's all."

"Even so, thank you once again for treating us." Kanae bowed. "Now then, will you let us leave?"

"Not yet." Kai replied. "The information you give is really useful for me. Because of that, it seems my dream can come true." He said. He then looks toward both of them with serious determination. "The dream of making the strongest Yakuza group of this country."

"But… I thought you're already belonging to Yakuza group?" Shinobu asked.

"No. My groups… Is being killed by an Oni." Kai lied. At least because of Kanae information about Oni, he can make a lie up story. He still didn't trust anyone to know the truth about him. "I'm able to get away. But my boss before his death, pleads to me to reinstate the group once again."

"I'm feel sorry for your group then." Kanae said with sympathy toward Kai condition. "If you not bother, what's the name of your groups?"

"Shie Hassaikai." Kai answered. Although during his time as villain Overhaul, he hold pride on his small Yakuza group. "For that, now I must search for a new group members. And I know who's the one that fit first." He then point toward the Kocho sisters. "Both of you are the first perfect comrades for my groups. Rather than live in the shadows, why don't you join me instead?" He bluntly offered.

Hearing that offer make Shinobu feel offended. "Don't joke with me!" She angered. "Why must we join a group of thugs like you!?"

"And yet that group of thugs is the one that saved me from being a street-rat." Kai countered. "If I must say, human personality is always the same right? Just kill something that's unknown to them. Your organization seems are no difference from your explanation. After hearing this explanation about Oni, I had something in mind. Why just kill them? Why don't you ever try to put them in your rule instead?"

"That's impossible." Kanae stated with narrowed eyes. "Oni... is creature that already submit to their instinct. Even till now, I've never seen one that not drive by their instincts."

"You keep talking about them like they're predatory animal." Kai stated.

"Yes! They're animal!" Shinobu yelled. Her brash attitude have taken over. "Have your head lost some screw or something?! All of them didn't deserve to live! Why must take pity toward them!? They're just monster that lied for their own gain! A calamity that should not exist! That's Oni! And yet you… You said you want to make them join your groups of thugs! ARE YOU SAID YOU JUST IGNORE MANY INNOCENT LIVES THAT FALL BECAUSE OF THEM!" She cried while panting from yelling.

"Then, let me ask you this." Kai speak up. "What about humans huh? You just trapped in a circle of happy family and never felt any misfortune from any human scum. And yet because of one Oni that give you misfortune, you hated them as whole? Why don't you try to see the bigger picture? Why not put them under us instead so we can have their destructive powers for our benefit?"

"You're sick." Shinobu scoffed, not understanding Kai's logic at all.

"The one that sick is you maybe." Kai said with impassive tone.

"Shinobu please stop." Kanae pleaded. "Don't offend him once again."

"But Big Sister, This man logic is so sickening to me. Sparing Oni lives meaning many innocent people died will not be respected." Shinobu stated.

Hearing the statement, Kai later tried to think of something that maybe will force both of them to serve under him no matter what. Then, a thought crossed his mind "What if I tell you... If somehow I can revert them to not being able to eat human again?"

The Kocho sisters later look at him, surprised by his statement.

"You… Can what?" Kanae asked.

Kai sighed. Seems tell another lie then. "Since little, I'm very gifted with human anatomy. And all due to the ability that I use to heal you Kanae. If what you said that Oni can't eat other than human, change their cell properties maybe possible. I once do it casually." He remembers his twisted act toward Eri, destroying and repairing her body continously for his **Quirk-Destroying Bullets**.

"That means…"

"Here's the bargain." Kai then stated his conditions. "You and your sister join Shie Hassaikai, and help me recruiting strong Oni for my groups so I can examine them." He then narrowed his eyes toward both of them. "However… Betray me, and I shall report your organization toward the government."

"There's no way they'll listen to Yakuza like you!" Shinobu yelled.

"Is that so?" Kai asked. "Care to bet about that?"

Kanae however knew what Kai had in mind. They can't win because they're now weaponless. He already holds all cards on his palm. More badly, if Kai Shie Hassaikai is a famous Yakuza group and he's not playing around with his threat because of his underworld connection with the government, then the Demon Slayer Corps will be in great danger because of the laws that they disobeyed. Even all of them, no matter how skilled they are, can't fight the more huge numbers of force from the current Imperial Army, who rumored beat the mighty Russian Empire in 1905. She then bit her lip. 'Forgive me… Oyakata-sama… Forgive me Kanao…' She thought about her master and her adopted sister before look toward Kai. "I'll… Join you…"

Shinobu clearly shocked about her sister statement. "Big Sister!? Please don't joke! You're joking right!"

Kanae however narrowed her eyes toward her younger sister. "Shinobu. Please silent for a while." She said, making Shinobu tensed. After the matter with her sister is settled, she then looks toward Kai. "However… I also have a condition."

"Please then talk." Kai replied.

"Just please… Don't ever report our organization toward the government or the great Emperor Taisho." Kanae stated. "You see, our organization also had many people and poor children that have no place to go after their family is being killed by Oni. As someone who's taken by your boss after you had no place to return to… You also understand their pain aren't you?"

Kai nod. "Terms accepted." He then brings his right hand forward for shaking. "Welcome to Shie Hassaikai. Kanae. Shinobu." He greets his two first comrades on this world, although they're force to join like many of his Expendable Bullets.

Kanae however forced to shake hands. "It was my pleasure." She said with neutral tone, agreeing the handshake.

'No need to worry Pops.' Kai thought. 'Sorry for this time, that I must break your teachings once more. But next time, I promise you Pops that I'll use your teaching to recruit other members.'

On Shinobu side, she can't expect by what she seen. "Sister…. What are you doing… Why..."

"Then tell me. Which one is the closest mountain from here?" Kai asked. "I plan to build my new base on the mountain, to avoid any suspicion."

"The closest mountain in here is Natagumo Mountain." Kanae informed. "We can reach there on night if we walk from here."

"Very well." Kai agreed. "You can come out from this house. I still have something to do first."

Kanae nod. She then look toward Shinobu. "Shinobu, let's go waiting for Kai outside."

Shinobu reluctantly nodded, agreeing with her sister. She then walked followed her sister to the outside, but not before giving a hateful look toward Kai.

After both of them is out, Kai later sighed. "It's fine now. You can come out."

From the cupboard that located on the edge of the house, the man and her daughter that's revealed to be owner of the house is seen come out. "Thank you very much young man. We forever in your gratitude for saving us from the thief."

"No need to think about it. I just help because those thieves annoy me when I ask your permission to sleep in your house." He said. "Thank you very much for lend me your house for a while old man. Don't get out until all three of us are far away from this house."

The man nod. "Thank you once again." He said.

Kai later walk to the outside of the house. But before that, the man's daughter ran toward him and touches his hand, which's surprisingly not produce hives because of his mysophobia. "Mr. Kai, maybe you said you were a Yakuza. But… I think you're a kind Yakuza to me." She said with a smile.

Kai later look at her and smiled, though not seen because of his mask. "I just want some redemption that's all." He replied and later walk outside the house. "Take good care of your father kid."

"Um!" The daughter nod.

* * *

When Kai is exiting the house, he's already been waiting by Kanae and Shinobu. Both without their **Nichirin** **katana** since Shinobu's is carried by Kai and Kanae's is being destroyed.

Luckily, all the stone spikes is already being destroyed by Kai secretly during the entire conversation to prevent them learn too much about his abilities.

"You're taking too long, Kai." Kanae said with a smile.

"Just to be clear here, bird-beak man!" Shinobu point her finger toward Kai. "We and my sister will never be part of your groups of thugs. Even if you reporting us to the government, I will defeat you first!"

"We will see about that." Kai replied. "For now, let's go to Natagumo Mountain that you talk about. Kanae, escort us to there. Shinobu, you stay behind." He ordered.

"Hmph! Even though you're screw lose you act like you're the boss." Shinobu scoffed as she walks.

"All right." Kanae agreed before walking alongside Kai while Shinobu is walk behind them. "Say Kai."

"What?" Kai asked.

"In truth, that people you killed was a thief right? You saved that man and his daughter. I think for a member of Yakuza… You're a kind person." She said with serene smile.

"It's not polite for hearing others." Kai scoffed. "And I'm not kind person."

"My my… You won't admit it then?" Kanae teased.

"Silence." Kai ordered as he walks forward. His journey of building the strongest Yakuza group in this world of Oni, is just beginning.

**Notes:**

**That's it for the second chapter! The next chapter will feature Kai encounter with Rui. Since this is before Tanjiro and co. came, the Spider Family at this time is still complete with ten members shown in Demon Slayers Anime Episode 20.**

**I know on this chapter that Overhaul personality shifts seems strange, but lets us get that in this time, he already admit that he failed his Pops by walking the path of villain and now is mellowing a bit to respect his old man teachings. That's why he ask for forgiveness in his thought to the old man for recruiting Kanae and Shinobu using lies and threat. I ask forgiveness for readers that love Kanae and Shinobu for the torture that Kai gives them in the early part of the chapter.**  
**And yes! Kanae and Shinobu are the first member of the new Shie Hassaikai that Kai will form in Demon Slayers. Maybe anyone wouldn't expect it, but I plan to make them the factor that makes Kai more mellowed and built his care for comradeship and trust, not through fear like he developed toward his Eight Expendable Bullets in BnH verse.**

**And yes. There are some Oni of Muzan that I plan to betray Muzan and join Kai new Shie Hassaikai. Don't forget that his Quirks allow him to separate Muzan Cells from the Oni's body.**

**See you in the next update!**


	3. Chapter 3:Overhaul Vs Shinobu Kocho

**/N: Boku no Hero Academia is written and illustrated by Kouhei Horikoshi. Kimetsu no Yaiba is written and illustrated by Koyoharu Goutoge. Rurouni Kenshin is written and illustrated by Nobuhiro Watsuki. I don't own the three of them.**

* * *

**How to read the story**

In the… – Normal

"You're…" – Conversation

'Why…' – Thought and telepathic communication

Kagune – Foreign words

"**Fired…"** – Deep Voice

**Tetsusaiga** – Technique, Quirk and special weapons

* * *

**Chapter 3**

**Overhaul Vs Shinobu Kochou**

After an heated argument and got an explanation that he needs about this backward age of Japan that seemingly had different history than his own, Kai finally got two members of his new Shie Hassaikai: Kanae Kocho and Shinobu Kocho. Both are forced to join after he makes a bargain with them to join him in exchange that their organization: Demon Slayer Corps is safe from being reported to the government by him. In other words, he forced them to defect from their Corps and faithfully served him.

And yes, he still uses the name Shie Hassaikai for his organization name. The name is the only way he can respect his boss for now, since he knows he can never return to his own world.

For now, he won't give them any kinds of weapons because he still not fully trust them enough for him to return their arsenal. Judging from the muscle built of Kanae and Shinobu, Kai deduced that both of them are an accomplished swordsman, although he sensed that Kanae is far stronger than her sister.

For now, his goal is to reach this Natagumo Mountain to build a new base for his new Shie Hassaikai. The reason why Kai's choosing a mountain or he can call hill is not only because it was far enough from society, it also help him to build an underground maze and room like his previous base using his Quirk, although he pretty sure that if Mimic is around, that work can go more faster.

Kai is walking along with Kanae and Shinobu, three of them are passing a crowded market. Of course not like the modern supermarket on his world where's electricity already play a part in daily life, but a traditional market where numerous people gather selling their crops.

"Kanae, must we cross here? This place is so full of dirty people." Kai said in discomfort, afraid that his mysophobia will kick in.

"I must buy supply first. Maybe some snack or something." Kanae replied. "After all, I and Shinobu haven't eaten yet since last night. But don't worry Kai. I'm assure you we'll arrive at night."

"You better hold those words." Kai grunted.

Meanwhile on Shinobu's side, she only walks in silence. Ever since her older sister accepting Kai's threatening join into Shie Hassaikai's member, she clearly didn't understand her sister decision. Why'd they must join his Yakuza's group while both of them can run after Kai's healing their legs? Even though Kai threat maybe deadly call, somehow they can-

Shinobu shook her head, dispersing those thought far, far away. 'No. I can't ever think to kill human. As despicable and illogical his decisions are.' She thought before look toward Kai's back. 'What do you mean by your statement that time? Why'd you just thrown your groups death easily like they're disposable pawn? And why'd you want Oni to join your Yakuza group? What did you see in despicable being like them? Who even have no reason to keep alive on this world? And what did you mean by seeing bigger picture? Human are also do the same as them? No. It's not true. It's not true.' She thought denied every word that Kai made during the conversation at that hut. 'For now, I must-'

"Um… Kai?" Shinobu called him.

"Hum… What is it Shinobu?" Kai asked while glanced to her.

"If you not mind, can I go to the bathroom for a moment?" Shinobu asked. "I see one during our walks in here."

Kai sighed. "For a second I thought what…. Fine. Two minutes." Kai allowed. "We'll wait you on the edge of this market."

Shinobu nod with a smile. "Thank you. I'm sure I won't late." She said as she turn around.

Kanae smiled seeing her sister. "I'm so glad. I can't believe she accept it so quickly." She said seeing the back of her sister.

"Was she always like that? Brash and act mighty?" Kai asked in curiosity.

"No need to worry Kai. She's actually kind at heart. Maybe like you, she just can't express it directly." Kanae explain with a smile that shown sadness on it. "Ever since our family is being killed by Oni, she's the one that took the incident the hardest between the two us. Although both of us made promised to kill every Oni that bring chaos toward humans, she also want to become strong enough to protect me despite her weak body." She then looks at Kai, who raise his eyebrow at the sad story. Kanae then laughed a little. "A ha ha ha. Sorry, seems I talk too much about my past, am I?"

"No. It's okay." Kai said. "She's the same as me I see… Wanting to protect something precious to her. I respect her despite her weak body, she at least trying." He said, complimenting Shinobu determination.

His words pick Kanae interest. "If you not mind Kai… How'd you end up in Shie…Hassaikai anyway?"

Kai however still conflicted. Should he tell Kanae a little about his past? Seems different than Shinobu, Kanae proved to be friendly despite his previous act toward her. But, he still not trust her enough. Not yet. But at least because she tells a little about her past, he need to be fair as well.

"When I was a little kid, my parent throws me away. If you want to know…You can touch my hand." He said.

"Um… Are you okay with that? I mean… You know…" Kanae embarrassed by Kai's request.

"Stop blabbering and just touch it." Kai ordered.

After some time, Kanae finally agreed and touch his hand and she then see some hives emerging on his hand. Kanae later back her hand in worry. "Your hands… What happen?"

"It's a symptoms called mysophobia. I since little had a fear of contamination and something that I deem dirty." Kai explain. "Because of this, my parents throw me away. I life as a street rat ever since then. That's when I thought… Humanity really sick and need a cure."

"Kai…" Kanae's voice shows sympathy on her tone. His word back then on the hut is true after all. She and Shinobu is life on a circle of happy family, unlike Kai. Because of it, they never know the true dark personality of humanity.

"That's when…. He comes." Kai said with nostalgic tone remembering the day his boss take him to join Shie Hassaikai. "He... Even though he knew I was just a thrown child, kindly took me in and called me his children. That's why… I'll never forgive anyone who disrespects him and the Yakuza." He said. "And for that reason… I've worked hard to somehow pay the debt of the boss. But… You know the rest of the story after that."

After hearing Kai's flashback, Kanae started to feel something different about the villain Overhaul. At first, she thought of Yakuza as a group of thugs who had no respect of people and terrorizing the district where they're resided. At least that's what their parents told her and Shinobu. But after hearing Kai's, she's start to wonder if somehow her view Yakuza being a group of thugs and outcasts is wrong by hearing what Kai's former boss acts by adopting Kai even though he's not his relatives at all.

Could it be Yakuza… Also contain some good people?

"Kai." The latter look at Kanae, who eyes is reflecting forgiveness. "After hearing your story, I want ask for your forgiveness." She later makes a slight bow. "Sorry for saying Yakuza is just a group of outcasts that loves to terrorize innocent people. After hearing what your boss did to you. I… Can't say a thing to argue about it. He must be like our leader Oyakata-sama."

"It's okay. Since you and your sister join me, I won't hold grudge. But the warning that I make that time is real." Kai dismissed the apology. "But… Oyakata-sama?"

"Yes. He's the leader of Demon Slayer Corps. Despite his illness, he's a very kind soul at heart. Every time he speak, his word is so comforting. He even views all of us in Demon Slayer Corps like his children…" Kanae said to Kai about his leader.

"Like his children huh?" Kai commented with no interest. "Say Kanae… What would you do after all Oni is gone from Japan?"

"I… Honestly don't know." Kanae admit before rubbing the back of her head. "Like you say… I'm too tight on the circle that created by my family…"

"Then, enjoy that." Kai said. "Being never experienced the darkness of humanity is good. I hope, you never experienced the same thing that I did."

Kanae nod with a smile. "By the way, I wonder where Shinobu is. It's been passing five minutes and she still doesn't come back."

However, Kai's mind already thought what scenario that'll happen. He knows that Shinobu really hated his guts that the best predicament is that she's running away to the base of Demon Slayer Corps and report him. Considering her brash attitude, of course she'll no afraid of his threats. But judging by both sisters care toward each other, she must be not far away. The best thing she can do is- "I'll search for her. Kanae, you can wait on the edge of market." He said as he walks searching for someone that maybe can become 'traitor'.

Kanae later waved her hand. "Come back safely." She said as she lower her hand. "The darkness… Of Humanity… I wonder… If what Kai said that every human had a monster of hatred inside their bodies… Is true…" She uttered to herself.

* * *

Meanwhile, true to Kai predicament, Shinobu is seen on the edge of the forest that's close to the city. Thanks to her physical abilities as a Demon Slayer, she can reach this place in few minutes. Now, she's already finish writing her report letter about Kai and her conditions and put it on her Kasugai Crow that waiting for her on the forest. She put it precisely on its feet before the crow flies off.

"Please Oyakata-sama… Help us…" Shinobu hoped that her letter will reach the Demon Slayer Corps.

However, that hope seems lost, because a rock spike suddenly emerged from behind her and impaled the crow, killing it instantly.

"I just let you go for a while and you started to show your true colors."

Shinobu tensed hearing the voice that too recognizable for her. She quickly turn back to find Kai standing facing her.

"H-how can you know that I'm here?" Shinobu asked. She's now completely helpless because there are no **Nichirin katana** for her to defend herself. Her crow is also killed. There's no way the base know what happens to them now.

"Who knows? Maybe luck that was a forest close to here that I know you're here?" Kai mused. "Different than your kind-hearted sister, you seem a brash brat aren't you?" Kai later bring his hand forward. "Seems I must use the old way to make you know your place." He then place his hand on the ground, Creating a giant stone dome to block Shinobu's way of escaping. "Judging from your location now, you seems have superhuman abilities am I right? If you're normal human, there's no way you'll reach here so fast." He analyzed.

Shinobu eyes are shadowed by her bangs. Her plan to ask helps from Demon Slayer Corps is failed before it even began. Her emotions now: frustrated.

"Now then, you plan to defeat me brat? Try it if you think you can." He taunted.

She later looks toward Kai with heartless eyes. "Why don't you just die? Not only a Yakuza, not only had a sick and twisted plan to make Oni join your stupid groups, but… YOU ALSO BRAINWASH MY SISTER!?" Shinobu yelled in anger, the emotions got the better of her. "Why!? Is what information you got not enough!?"

"Who's said I brainwash Kanae?" Kai dismissed her accusation. "If I must say… She's the one of few persons that got my genuine respect. I also hold some respect for you. But… In the rules of Yakuza this is a betrayal." He plainly stated. "However, you still had some use to me."

"You're the one who forced both of us to join you!" Shinobu argued. "And the fact that you killed that poor house-owner because he's annoying you is making me sick!"

Kai later sighed. "If that's a fight that you want-" Kai later take a stance. "-Let see you'll match me with that small body of yours." Kai later summons another stone spike barrage by putting his hand on the ground. Shinobu strength is only her agility. She uses it to deflect most of Kai attack. 'For a small body she's sure agile. However, I can guess she's aiming for her **Nichirin katana** on my waist.' Kai deduced.

'Ugh. What kind of strength this man have exactly? There's no way he's an Oni! That bastard can walk on daylight. But he somehow had the ability to create stone spikes from the ground plus his hand is also dangerous. Not to mention the speed of the stone spikes is extremely fast.' Shinobu analyzed while take a breath for a while.

"If you want your **Nichirin katana** that much." Kai suddenly exiting his battle stance, standing like usual. "Come and get it if you want." He challenged.

"You're bluffing!?" Shinobu said in disbelief.

"Well, a woman with such a weak body like you maybe can't do it. After all, Kanae is more talented than you." Kai said, trying to make Shinobu snap.

That plans is worked easily. Filled with anger, Shinobu later rush forward toward Kai, who standing calmly. 'I got it!' She thought as she reaches her **Nichirin katana**.

"You're in my attack range." Kai said as he uses his **Overhaul**. His left hand slapped Shinobu right hand who tried to reach her **Nichirin katana**, exploding it into blood splatters.

Shinobu is clearly shocked by what she saw. 'This technique… Is this the one that he uses to kill the owner of that house and heal us?' Shinobu thought as she fall face first to the ground. Her body is dragged several feet because of the fall.

"You're got speed I give you that. But, you're too handicapped because of your anger." Kai stated while glanced toward her. He then walked toward her.

Shinobu later managed to sit up. Her hand is holding the stump that once her right arm. Her face is showing exhaustion because of blood loss that's cause by the attack. Her face showing anger.

"You know what." Kai said as he squat down when he's close enough. He then use his **Overhaul**, going to create stone spikes that used to bind her. However…

"You let your guard down." Shinobu said as she managed to catch Kai by surprise, taking her **Nichirin katana** back. She later rolling down and managed to stand up despite her injuries. "If you keep underestimate me because of my small posture, that'll be your downfall."

"Keep talking like that. I know that your specialized in stabbing technique am I right? Judging from the thick muscle in your elbow and palm, your thrusting power is enough to make a hole on a tree." Kai revealed his actions of examining her anatomy during their stay on the hut. "Just stop this already. We're going to waste time to Natagumo Mountain if it became like this."

"You're know that much. Then I shall say something, Kai Chisaki." Shinobu later making a stance for her thrusting attack using one arm. "I won't join you Yakuza group! I rather die than join groups of thugs!"

"Very well. Your death wish." Kai later take his battle stance. "I'll make your wish come true."

'Judging from what he displays till now, he must use his hand for his ability to be activated. I'll aim one of it in the joints. Then another maneuver for another. Then the victory is already decided.' Shinobu planning her attacks.

'From what she's look, she's aiming for my arms. Then, the best chance is to destroy either her remaining arm or her sword.' Kai seems already knows what Shinobu's aim.

Shinobu later begin her attack. "**Dance of the Butterflies.**" She later dash toward Kai with incredible speed.

Kai later act quick. Using his other hand that's already on the ground, he summon several rock spikes that darts toward Shinobu.

"**Frolic!**" Shinobu later use her sword techniques which consists of multiple stings thrust toward the rock spikes, shattering it.

'He can destroy those rocks!' Kai thought in surprise.

Shinobu later delivering a thrust toward Kai, who block it with his other hand, making the unique-shaped **Nichirin Katana** pierce through Kai's arm. At the same time, the power of her attack is stopped. 'He's sacrifice one of his arm to stopping my thrust!?'

"You attacks are all futile. Seems your so-called **Wisteria Poison Concoctions** only works exclusively for Oni." Kai pointed as he let his pierced arm pierced more further, destroying Shinobu **Nichirin katana** with his **Overhaul **using his other hand, turning it into dust. He later delivering a powerful kick toward Shinobu chest, making the Demon Slayer thrown several feet before fall and crashed on the ground. She later coughed some blood while struggling to stand up. "Now give up. With that much blood loss, you can't beat me."

However, Shinobu doesn't give up yet. "Go to hell!" She roared as she jumps to the air before diving down toward Kai to kick him, revealing that her sandals is hiding a sharp knife.

However to Kai, this is just a futile effort. With both of his hands free, he uses some of his maximum speed like when he faces Rappa. When Shinobu already pass him, all of her limbs are exploding to blood splatter, while Kai only receiving slashing wound on his cheek.

"Im..possible…" Shinobu only managed to utter as she roll and later stops with her backs on the ground. Her small body is getting weaker due to blood loss.

"You can't win against me, Shinobu Kocho. Not with that speed of yours." Kai said as he glanced to her before walking toward now paralyzed Shinobu. "Now, what shall I do with you?"

Shinobu face now changed after struggling to sit up with her remaining arm is the only support. Instead of showing anger, it shows pure fear toward Kai. Never once on her life she faces someone like him. Even the Oni that she managed to kill thus far never displayed this high-level intellect and quick reflexes during combat. All of his attacks are precise, but her attacks are not.

In other words, the winner is already decided since Kai managed to make Shinobu snap, using the monster inside of her for his own advantage. He already holds the game plan since then.

"So, you're afraid of me now?" Kai asked menacingly as he squat close to her. His hand later going to touch her cheek, seemingly to kill her by the same way when he kill Magne.

Shinobu body later shaking. All her instincts tell her to run, remembering what he can do using those hands. But, her body don't support her. She later closes her eyes in fear. 'Big… Sister… I'm sorry… Please forgive me…'

Before his hand touches her cheek though, Kai turn it into fist, and he punched Shinobu face hard, making her fall to the ground. "You think I will kill you?" Kai asked her. Kai later fixing her hands and legs back to normal using his Quirk. "Tch. Waste of time."

"Why…" Shinobu uttered before fall unconscious.

"Why you said?" Kai said as he carried the unconscious Shinobu on his shoulder. "It was simple. You also got my respect. Your determination to protect your sister is amazing. The same as me toward Pops." Kai said. "For me to reinstate Yakuza in here, your power is needed, because I had faith on you. Besides that, I already promised to her."

* * *

The time later shows evening, Kanae is seen sitting on one of Dango restaurant, chewing one Dango on her mouth. "Hmm… I wonder why they had taken so long." She hummed to herself.

"Kanae." Kanae later saw Kai who hold the unconscious Shinobu on his back. "Change of Plan. Seemingly we must search for lodging or something before continuing our journey tomorrow."

"Shinobu..." Kanae is worried seeing her younger sister. "What happened?"

"No time. Search for the closest lodge now." Kai ordered.

"O-okay!" Kanae said before running in search for a room.

* * *

Fortunately, Kanae managed to found the closest lodge for night. While Kanae insists Kai to sleep inside if he wants, the villain Overhaul more choose to sleep outside.

Kai is seen sitting on the garden of the lodge, currently thinking about a way how to ask Oni to join his groups of Yakuza. Judging from Kanae's explanation is more fit to call Oni as Muzan faction: a group of immortal superhuman. He pretty sure that if Muzan is behave like him in keeping his underlings in check, he must be use some kind of threat or something.

'Seems this recruitment will become harder than I thought.' Kai thought in little frustration.

"I'm glad you're here." Kai later turn his head to the left to see Shinobu is standing facing him. She already recovered from her injuries after Kai painfully deconstruct and then reconstruct her body using **Overhaul **while on the process she's still unconscious. She's now seen wearing a sleeping clothes while a blanket is seen wrapping on her upper body to protect her small body from cold. Her face is showing a neutral look.

"What? You're healed already and want to challenge me once again?" Kai asked while his hand is ready on his gloves.

"As always, your jokes always dark." Shinobu commented.

"I take that Kanae already asleep then?" Kai guessed.

Shinobu nod. "Kai Chisaki. I want to talk to you. Do you have some time?"

Kai raised his eyebrow before sighing. "Well, this is something new." He commented.

"But, we won't talk in here." Shinobu said.

* * *

Later, they are walking on the street of the village, leaving Kanae who already fall asleep on the lodge.

"Then, what do you want to talk about? I know you don't come here just to walk alongside me aren't you?" Kai demanded. "I rather rest now for the journey toward Natagumo Mountain tomorrow."

Shinobu later look down while walking. "I know… It sounds very late. But… Thanks… For saving my sister. Whatever your reason are." Shinobu uttered the words.

"Kanae also said the same thing. You should remember though I helping her for my own gain." Kai replied. He then decided to ask something he's very curious of. "Both of you care for each other so much, am I right?"

Shinobu widen her eyes, before huff in annoyance. "Humph. Seems anything can't escape from your analysis isn't it?"

Kai didn't reply her annoyed tone.

Shinobu face later turn serious. "Big Sister already told it to me. About your past."

Now its Kai turn not expecting that Kanae dared to shared his flashback to her sister, which he not trust fully. "Why'd she tell that without my permission I wonder?"

"She said she's falsely judge you after he heard that you being thrown away by your parents." Shinobu replied. Her face also showed some guilty look for judging Kai as simple thugs. "And after I hear it, I can't help but wonder what you said in that hut is because of what your parents do to you. Even though I was accomplished Demon Slayer, I really a fool when it comes to judge people personality."

"I see." Kai commented with little interest. "If you not mind, how exactly you circle of happy families lived huh?"

Shinobu at first hesitated. Did she really need to tell Kai about her past even after she knows the Yakuza flashback from her older sister? She then takes a deep breath before beginning to talk about her past. "Like you said during that time on the hut, my sister and I lived in a very happy family. Our parents is loved us very much and very expert in medicine compound. Because of the happiness, I've always thought that happiness will go on forever."

"Foolish way of thinking." Kai pointed bluntly. "Live is not like flowing water. Sometimes the water will block and go to another direction, sometimes it will also dried up and change to barren wasteland."

"You're right." Shinobu agreed. "One night changed my view about the world. A Oni is came inside our house. Kanae and I managed to hide on the wardrobe. But… My parents… They're dead." She said with a sadness clearly shown on her tone. "During that time, a Demon Slayer is saving us and take us to their base to train us to become like them."

"Are your organization is so desperate that it needs children to be ready for killing Oni?" Kai asked, clearly confused with how Demon Slayer Corps work.

"We don't mind about that." Shinobu shook her head. "In fact, because of it, my sister and I have new resolve: To protect the happiness of everyone that yet to be destroyed by killing Oni. That's why both of us make my promise to defeat as many Oni as possible to prevent the same tragedy happens to anyone."

"A Hero's goal huh…" Kai commented with a little disgust. "So you want to be hero of justice huh?"

"You seemingly hated when someone have a dream of saving someone. What is happen to you actually?" Shinobu is curious. Why'd Kai always seemingly angry when hearing about heroic goal?

"Not your business." Kai dismissed the topic quickly. "Then, that's the time you made a resolve then?"

Shinobu nod in agreement. "Although that's the promise we made, both of us have separate dreams. My sister is suddenly grown a great sympathy for Oni after knowing they're former human. She even has an impossible dream that is where Oni and Human can live in harmony without trying to kill each other. I myself do not understand why she had ever dreamed like that. Why we must feel pity for creatures that feed on human? That's something so illogical." She expresses her disagreement with her sister dream. "Like your dream of putting Oni under your Yakuza." She said. "I even now still not understand what you mean by looking at the bigger picture…"

"Then let me explain a little about my abilities. I put off that statement because I already think ahead." Kai said. "My special abilities allowed me to deconstruct anything to molecular level and then construct it into anything I desired by just a touch of one finger. I'm pretty sure you experienced it yourself four times am I right?"

Shinobu later feel one of her arms is shaking, making her must grip it with another arm. The fact that deconstruct must happen first is still haunted her mind, particularly on the battle where Kai able to defeat her easily with some injuries on his arm and face. "I…"

"Like I said before, when I already know the composition of their cells, it is easy for me to disperse the specific cell on their body. That's why I ask you and Kanae to join under me." Kai explaining his reason of seeing the bigger picture.

"I… See. I thought you just… Imagining about it. Like my sister does." Shinobu said in understanding. "But still, how about those innocent souls who died because of them?"

"Sometimes in need to forgive a single person mistakes, we must ignore the pain of many that caused by one person." Kai replied. "Based on everything you and your sister told, this Muzan Kibutsuji is the real problem that need to be eliminated rather than wasting time killing his underlings left and right. Heck, even your sister said that Oni personality is the twisted version of their original one right? Meaning that Muzan cell is the one that we must pull out no matter what."

"Easy to say. Since Sengoku Period, no one has ever seen him or know where's his hideout." Shinobu said.

"Then why not you capture an Oni and forced him to tell where he is? I bet your strength is easy enough to capture one of them and forced them." Kai asked the most logical solution possible.

"That impossible." Shinobu said. "After turning someone into Oni, Muzan place a curse on them that'll make die if any of them ever utter or said his name."

"A coward then. If he really that strong like your organization claims, he should be holding his name in pride. Seemingly he's just a brat that lives for thousand years old according to me. A truly waste of time." Kai said his disappointment to the Ruler of the Night in this world. Compare to Tomura and All for One, Muzan is a delusional fool who so arrogant and maybe such perfectionist that have child mentality, while both Tomura and All for One already have charisma and great abilities to back them up plus their genuine care for their comrades. "The one that served him is a fool then. Why they served some fool arrogant and immortal brat that have such simple goal?"

Shinobu never expected Kai dared to bluntly mocked Muzan like that. As a Demon Slayer she should worry about talking such words. He could be everywhere. "I… Really don't know much about his abilities. His **Blood Demon Arts** and abilities is also mysterious to us. The only thing that we know is his blood that can transform someone into an Oni."

"Your organization surely wasting your time huh? Chasing such coward." Kai said while sighing, disappointed with how Demon Slayer Corps unable to capture just one man for thousand years. "Then, do you know about his ultimate goal?"

Shinobu shook her head. "No. Like I said before, we never met him face to face."

"To beat an opponent, one must know his ultimate goal first to plan a great attack to bring them down." Kai mused. "If that so, I'll challenge him."

"No Chisaki! There's no chance you'll win against him!" Shinobu warned. "Numerous Pillars of the past already tried to fight but instead they're always being killed by his special forces: Twelve Demon Moons. If that time you didn't arrive… My sister maybe will…."

"We don't know unless we try isn't it?" Kai countered. "Besides, judging from every information you give to me, I'm pretty sure that he never trained once on his life. His regeneration is the only one that help him survive."

"I truly don't know why you are so confident about this." Shinobu said. "But… If you somehow able to do what you said, will you help my sister dream then?"

"Depends." Kai replied. "If it also profitable for me. I'll consider it."

"Then… At least I'll say thank you." Shinobu thanked. "Then, I'll go to the point of this talk."

Kai later look at her intently.

"Even after you beat me that time and no matter how my sister is warm up to you Kai Chisaki, let me stated something. My sister is everything for me. So-" She later look toward Overhaul with a serious look. "-Although it's being forced, if you can make my sister smiled and happy, I'll join your little group of thugs and… Throw my life and pride as a Demon Slayer for a while. However… Don't do that, I rather choose death than join you."

"Nothing that I'll say changed your mind huh?" Kai asked. "I can't guarantee that you know."

"Are you sure about that?" Shinobu asked with a smile. "Maybe you're expert in medicine and anatomy, but you're never examined the anatomy of Oni. I on the other hands know very much about the medicine to cure wound cause by Oni. I can said that if you doesn't make my sister happy, you'll lose the biggest asset for your new groups Kai Chisaki." She stated her actions if the conditions are not met. "How's that? Not a bad bargain huh?"

After those words, Kai is silent for a moment. Many thoughts are running on his mind. He never expected that Shinobu is managed to corner him in term of bargain. She has a point that he didn't know Oni anatomy at all. He at least must have a partner with extensive knowledge about Oni.

And that person is happening to be Shinobu Kocho.

"Like I said you're truly fit for a Yakuza huh?" Kai said in defeat. "You've managed to corner me this far…" He then raises his hand for a shake. "…Make me more respect you than ever before, Shinobu Kocho. If the group is complete, I'll make you my personal assistant. That also for your sister."

"Thanks for receiving the bargain." Shinobu thanked while receiving the handshake. "I'll join you but that doesn't make me your friend do you understand?"

"You act mighty toward me. How bold." Kai commented. "I understand about that."

"And yes… Before this conversation is finished, I have other conditions if you not mind." Shinobu said. "My sister said that Yakuza boss who took you in is a kind old man. Would you show to me that your Yakuza would be the same as him?"

Kai silent for a moment before answered. "We'll see about that."

* * *

Later in the morning, the three of them already check out from the lodge and continuing their journey toward Natagumo Mountain. Currently, they're in the open plains that shows Rice Paddy field not far away from their location. For the conversation last night, it ends well. Seemingly Kai and Shinobu already cool down.

Which is the fact that noticed by Kanae Kocho. The Flower Pillar of the Demon Slayer Corps is seen with a smile seeing it. She then decided to talk to Shinobu. "Shinobu. I think… You and Kai tension is down now. Can I ask why?"

"Nothing is happen Big Sister." Shinobu replied. "I just beat him in term of talking that's all. Isn't that right Chisaki?"

The one that is called is sighed in annoyance. "I won't tolerate it anymore if you keep talking like that. Just focused on the road toward Natagumo Mountain."

"Alright then, Okashira." Shinobu jokingly replied

"My my..." Kanae giggling seeing it.

* * *

The three continuing their journey until it finally reached sunset. Not long after, they've finally reached Natagumo Mountain. It has the appearance of a huge mountain like-hill that covered with huge trees and a waterfall and streams are also seen.

'Heeh… A perfect spot.' Kai thought. This mountain-like hill is more than promising. It was a perfect place for a new base for his new Shie Hassaikai.

"Well Kai, this is Natagumo Mountain." Kanae said, presenting the mountain that known as the beautiful sight on this time. "What do you think? Isn't it beautiful?"

"More than perfect to make a base." Kai replied with satisfied tone. "You're done a great job Kanae."

"Thank you Kai." Kanae said.

"But don't forget that we must get ready when Oni is around." Shinobu warned. "A mountain that so far from villages like this is the perfect hideout for any Oni."

"Someone that smart already knows that." Kai accepted the warning in sarcastic tone. "And the forest must be giving them the advantage they need." He then looks toward Kanae and Shinobu. "Did any of you have plans? Because I still need to know a little about the way Oni fight."

"Giving about your abilities, my strength as the current Flower Pillar, and Shinobu as my planned successor. I think is more than enough." Kanae stated.

"Flower Pillar?" Kai said in confusion.

"Pillars are the strongest swordsman in the Demon Slayer Corps." Kanae explain. "Excluding me, there are other Eight Pillars who stationed on their each region. Luckily, this area is still on my watch."

"I see. Meeting one of them is not what I want right now." Kai commented. "Now then let's go to that mountain shall we. We'll recruit some Oni."

"Right!" Kanae agreed. "I hope there some kind Oni in there that can negotiate with us."

"Don't hope too much on bloodthirsty creatures Sis, Chisaki." Shinobu warned. "Purge all of them. That's all."

"Come on Shinobu…" Kanae said.

"There's not much time. Let's go." Kai said as they walk to face any obstacle on Natagumo Mountain. The quest for building a new base for new Shie Hassaikai starts now.

* * *

They've finally at the mountain foot at night. Now the landscape of mountain is truly seen. The trees are full of spider web. Well, this mountain is commonly used by scientist to study the species of spider of Japan that lived here, being mentioned as the conversation area for various spider species.

"Well, they said this place is the conversation areas for Joro Spider, Tsuchi Spider, Mizu Spider, and many others. Truly fitting all the information that I've read." Shinobu said in awe while playing with one spider on her fingers. She always heard this mountain as spider paradise, but this is the first time she ever set foot on this mountain personally.

"Because of that, we must keep the destruction of this place as minimum as possible. These spider didn't do anything wrong." Kanae said to Shinobu and Chisaki.

"A bunch of little creatures won't disturb our base. A natural barrier in fact." Kai said after seeing the collections of spider that resided on this mountain. "Still no sign of Oni everywhere it seems."

"Maybe there are no in here after all." Shinobu said. "Seems even Oni have their own standard of clean."

"If that's the case. Then-" Kanae stopped her talking when she heard some rustling like some fights is going on.

"I see that they're seems reside in here." Shinobu commented before running to the direction of the voice.

Kanae nod, agreeing with her sister before look toward Kai. "Let's go to the source of the noise." She said.

"At last." Kai patience paid off. He and Kanae later running to the direction of the voice following Shinobu.

* * *

"AHH!"

"This is what you got for trying to run away from me, Eldest Sister."

Not far from the location where Kai and the others, there are some torturing happen.

A young girl is seen being hanged by what that's look like metal strings. The girl appearance is a pale, milky-white skin white, red dot on each side of her face and blue eyes. Her hair is white and reaches her shoulder and she wears white outfit. Her skin is shown some slash wound that caused by the metal strings.

Her tormentor surprisingly is an Oni with the appearance of a young boy around ten to twelve years old. His skin is white, with red dots. His hair is light pink and bears resemblance to spider legs. The sclera of his eyes are red, while his irises are pale blue. He also wear the same outfit as the female Oni that being ensnared.

Beside him, another female Oni is seen watching the entire ordeal with neutral look on her face. She has a completely pale, milky-white skin complexion with snow white hair and her eyes are pure white with only her silvery pupils separating them from her sclerae. She also possesses several red, dot-like patterns on her face. She also wears the same white outfit.

The female Oni that being trapped by the thread struggling to escape. But to no avail.

"This is your punishment for dare to run away. At least my other older sister still has her minds right to stay here and becoming my family." The boy Oni said with bored tone. "You punishment will be hanged close to home until the sunrise."

Hearing it make the female Oni that stand beside him is stunned. Her neutral façade is almost broken, showing some concerns look at the other female Oni.

'So… This is what I got…' The female Oni that being ensnared by metal threads seemingly accepting her fate. She looks down with a tear is rolling down her face. 'I'm… Truly such a fool…'

The boy Oni later preparing to do something using his hand when Shinobu suddenly jumped behind him to deliver a stab using her hidden knife on her feet. "Die! You monster!"

"Rui!" The female Oni that standing beside the boy Oni now known as Rui suddenly jump to block her way from reaching him. Raising her palm forward, a stream of spider web is racing toward Shinobu, who unprepared for the sudden attack.

Suddenly, Kanae appeared out of nowhere and kick the female Oni in the face, throwing her several feet before she can regain her balance herself. The strings that she utilized then just dropped to the ground.

Shinobu smiled seeing her sister arrived in time.

Meanwhile, the female Oni can't believe her attacks can be deflected. "She's deflecting my attacks easily!? It can't be!?"

"An annoying guests is come I see." Rui commented with disinterested tone. "Older Sister, take care of them. My business with Eldest Sister is still not finished." He then continues his torture, which later revealed that the string is coming out from his finger.

"Strings huh. A very useful abilities I see." Kai then appeared from dense undergrowth.

"Don't disturb the peace of my family, intruder." Rui stated while looking with bored look toward Kai.

"For a brat you surely had that much talking." Kai said before suddenly he swipes his hand on the air, which is revealed destroying the strings that entangled the Eldest Sister Oni, setting her free. "I'll discipline you to submission."

"STAY AWAY FROM MY FAMILY!?" A loud voice is then heard. When suddenly, a huge boulder is thrown into the battlefield, creating a dust that obscured the eyes.

"Let's retreat for now Older Sister." Rui ordered with menacing tone. "The time is to narrow. Leaving Eldest Sister to die at the hand of Demon Slayer is already enough for me." He said before running to the deep undergrowth of the forest.

"A-alright!" The Older Sister Oni, agreeing before suddenly jump backward and following Rui.

"Wait you!" Shinobu is about to chase her.

"Let her." Kai ordered Shinobu as he cleaning himself from the contamination. "So finally we met with Oni huh?"

"It seems." Kanae agreed. "But since it was close to sunrise, I think all of them are running away back where sunlight can't touch."

"Well one hadn't running away." Kai said while pointing toward the Eldest Sister Oni.

The Eldest Sister Oni is seen sitting while look down to the ground. The injuries on her body already healed, but her acts of being betrayed by the member of family she befriend her still haunt her.

"Hey girl." She then looks up seeing Kai called her. "Why not going to some dark place for a talk huh?"

**Notes:**

**And that's for Chapter 3! It maybe have some minor confrontation with Rui, but I promised the true confrontation begin in Chapter 4 till' Chapter 5!**

**As for Shinobu Vs Kai, I made Kai winning for good reason: The first is that his reflect move is so fast that he can utterly destroy Kendo Rappa with no effort. The second is that Shinobu angered state and the loss of limbs that deciding the victory.**

**For one that still not knows about the Oni that saved by Overhaul, Kanae, and Shinobu, she's another Older sister of Rui Family from Anime Flashback of episode 20. The one that advice the canon Older Sister Spider Demon to run together to escaping Rui's clutches only to be betrayed.**

**See you in the next update!**


	4. Chapter 4:Natagumo Mountain

**/N: Boku no Hero Academia is written and illustrated by Kouhei Horikoshi. Kimetsu no Yaiba is written and illustrated by Koyoharu Goutoge. Rurouni Kenshin is written and illustrated by Nobuhiro Watsuki. I don't own the three of them.**

* * *

**How to read the story**

In the… – Normal

"You're…" – Conversation

'Why…' – Thought and telepathic communication

Kagune – Foreign words

"**Fired…"** – Deep Voice

**Tetsusaiga** – Technique, Quirk and special weapons

* * *

**Chapter 4**

**Natagumo** ** Mountain**

The Eldest Sister Spider Demon doesn't know where to go. Three mysterious people suddenly arrived and managed to stall Rui long enough till' he forced to flee because of the incoming sunrise. The two female she already know as the Demon Slayer from their uniforms despite their lack of **Nichirin Katana**, but the male is unknown to her. She never saw a Demon Slayer with strange uniform like Kai.

"T-talk!? Wh-what are you talking about?" She asked in fear.

"Do you think I'm people who just kill someone without question?" Kai raise his eyebrow. "I can say that you're Oni of this mountain am I right?"

However, what Kai got is the Eldest Sister jump backward and creating a formation of webs from both of her palm and shoot it directly toward Kai. Kai later protect himself, but the webs are wrapped around him, restricting his body. "What the…"

"Kai!" Kanae yelled in concern.

However, the Eldest Sister wasting no time and also shooting the same web toward Kanae and Shinobu. Kanae managed to avoid it due to her speed as a Pillar, but Shinobu is second too late and also get entangled like Kai.

"Shinobu!" Kanae worried that her sister got caught.

The Eldest Sister is seen keeping her distance, seems satisfied with her results. "Talk to me? That's fun coming from being who killed our race without question." She said with an evil grin. "Anyway, it's useless to struggle. My **Blood Demon Arts** allows me to create super sticky webs. Once get caught you can't get away no matter how hard you're struggle." Her claws later lengthened. "And for the closing act. I'll inject paralyzing poisons that keep you in coma for few days."

Kanae however took notice of her words. 'A Paralyzing poison!? But why-" Does that mean this Oni had no intention to kill them in the first place? However, she must be careful. Oni are creatures that full of lies. They relied on anything to survive. At least that's what she heard from the other, more experienced Pillars.

"I see. Your **Blood Demon Arts** work like the Mexican Net-throwing Spider huh?" Kai guessed as he free himself by destroying the webs using his **Overhaul**. "But sadly, you're not on my level yet."

"B-but how!?" The Eldest Sister asks in fear. "My web should be-Uugh!"

The Eldest Sister is grunted in pain as a rock spikes is piercing through her body from her stomach. Kai is later seen already put his hand on the ground to deconstruct the terrain using his Quirk.

"Seemingly, Oni is the type that attack first, ask question later huh?" Kai commented. "Seemingly the sunrise is only few minutes to go. In that case." Using his **Overhaul **once more, Kai created some kind of stone dome by constructing the previously deconstruct terrain. He also still leaves some small holes so the sunlight still reaches the dome. He later deconstructs the rock spikes that stabbed Eldest Sister, make her fall to the ground while the wound is immediately regenerated. Although the hole in her clothes still remain. 'Amazing regeneration… So this is Oni.' Kai thought in amazement.

"He can create something like these!?" Kanae said in amazement since she never see Kai's Quirk work on the terrain.

"This brings some bad memories…" Shinobu uttered remembering her crushing defeat by Kai.

"Kanae." Kai called her. "If I not wrong, you have a dream about how Oni and humans can live in harmony right?"

The Eldest Sister gasp hearing it. A world where human and Oni live in peace? Talking about funny joke. That's because, she already know what standard of that world to become come true.

The one that's called nod. "Yes. However, this Oni must be already eating several humans. So I don't think she can be redeemed. Because no matter what reasons she did this… Killing humans is unforgivable."

"It's not time for that Hero sickness to kick in fool." Kai is upset by her response.

Shinobu however, remembering what Kai said during their time in the village. However, was it worth to forgive an Oni that's already having a taste of human flesh?

"Idiota…" The Eldest Sister suddenly uttered with Portuguese language.

His word is caught Kanae attention.

"I… Can't believe it. But I agree with the bird-beak man." The Eldest Sister said with a hint of anger. "Do you honestly think just because that man is the one that twisted our personality to be like this and make us unable to eat anything other than human flesh… Make us entirely a scum that not fit to life?"

"That's the truth." Shinobu replied. "All of you not even a living being. Just a scum of darkness that all deserved to be erased from this land."

However, the Eldest Sister muffled for a bit, before chuckling. "Khu khu khu… A Ha Ha Ha Ha Ha! A fit answer from organization that kills an Oni without question! You hate us so much... That you denied humans true nature that are more evil than us, being that only focused on their feral instinct to survive!"

Both Shinobu and Kanae narrowed her eyes with her statement.

Kai however, decided to sit and watch. He was interested in how this conversation will go on. However, he agreed on one thing this Oni said. Human are beings that are more evil than any kind of creatures. They're so full of greed, mostly to survive.

"Surely your claim always makes me laugh!" The Eldest Sister said with hateful look. "Then… Even if the Oni is the one that forced to transform by him and tried their best to fight his influence or still have some speck of kindness in them, will you said the same?"

Shinobu still not changed her demeanor at all. "You think we care about that? Once a human become Oni, they already abandon their humanity."

Kanae however had a different expression on her face. "Being… Forced to?" Does that mean not all Oni being transformed by Muzan because they want to?

"Even if I tell the reason why… You'll never understand. After all, no matter how kind human claim to be… They're never tried to understand something that's different from them… Am I right?" The Eldest Sister keeps taunting.

"T-that's not true!"

The Eldest Sister later look toward Kanae, who denied her claims.

"What you're saying… It's not true." Kanae denied. "You see… I have a dream to make a world where Oni and humans can live in harmony. I pitied all of your kind. Truly I am. Because of it… I want to make that dream come true."

"If that so… Then killing all of us is what you're called pity? How about the others Oni who want to atone for their sins? To reach a dream, someone must take a risk for it to be come true. All humans do the same, even betraying the one that trust them." The Eldest Sister retort. "Then where the world that you promise world will happen? In the afterlife? Don't joke with me."

"I-" Kanae is unable to argue with her claims.

"Just let me die okay?" The Eldest Sister said with disinterest. "I don't want to hear anymore nonsense from someone who wishes something like that but joined people who dedicated themselves for slaying us."

"But-"

"Silence Kanae." Kai finally joined the conversation. "Oni-onna, just forget that opening conversation and go to the business shall we?"

Eldest Sister looks toward Kai for a while before smiling. "Your eyes… Is different from these two."

"That's because I've seen the humanity darkness and goodness already." Kai replied in honest tone. "So don't worry. Both of us who see humanity hatred and short-sense of seeing only small justice in front of them can become friend pretty quickly."

"I see." Eldest Sister then smiling, however it is different from evil grin she showing earlier. "Then, I want to say thank you very much for saving me from Rui. Said that as well to this self-righteous Demon Slayer."

Kanae is stunned being called like that, while Shinobu tried her best to holding her anger for this Oni who insulted her older sister and honest dream.

"Back to the business already." Kai dismissed the gratitude. "Now to become more civilized, I want to know your true name first. Who's your name?"

Eldest Sister is silent for a moment, before finally speak up. "My name as human until now… Is Sofia Shion. Like my namesake, I'm Portuguese."

"You're a foreigner?" Kanae clearly surprised, she never heard of an Oni that from a foreign country. All of the Oni she's slain are Japanese so far.

"And what if I am?" Eldest Sister, now known as Sofia said. "I'm not talking to you."

"That's enough!" Shinobu can't hold it anymore. She later walk toward the female Oni, ready to pummel her even she knows she doesn't have her **Nichirin katana**.

However, Kai suddenly raise his right arm, blocking Shinobu advance.

"Chisaki! Stay out of this!" Shinobu yelled. "That monster insulted my sister enough!"

"She's already civilized enough to want to talk to us. Don't make this meaningless just become some petty insult." Kai said with narrowed eyes before look toward Sofia. "Sorry for that. You can continue."

"Thank you, Um… Who's yout name?" Sofia paused since she still didn't know Kai's name.

"Kai Chisaki. But you can call me Kai." Kai introduced himself. "The one who angry over there is Shinobu while the other one is Kanae. To justify something, the three of us not from Demon Slayer Corps like your claim, so you can relax."

Sofia at first hesitant, before nod. "Okay. Then, tell me the reason why'd you save me from Rui, Chisaki-san?"

"Before then, I heard about your master or something like that from Kanae and Shinobu. He seems like a coward according to me. Seems he never had an experience leading an organization huh?" Kai mocked Muzan ability of leadership once again. "What're your opinion about Muzan?"

"I can't help but agree." Sofia agreed. "That man is not a leader type like my king in my homeland."

Kanae and Shinobu widen their eyes, not expecting that an Oni that created by Muzan is mocking her master with delight.

"I take it that you've been forced to join is true then?" Kai asked.

"Not forced to Chisaki-san. However… I can't tell you the reason. That man cells will kill me if I ever utter his name or broke any information about him." Sofia said with a hint of apology.

Kai then decided it is time. "Will you kindly give your blood to me?" He asked.

"Eh?"

"I can somehow cure and expels these cells from your body. But to do that, I need a blood from Oni to be examined." Kai explaining his reason.

Sofia pull up the sleeve of her right hand, showing her milky white skin. "Take as much as you want. If I can only help to defeat that man using my blood, is more than enough for me."

Kai nod. "Shinobu. I know in your pocket you have some small bottle or something. Give that to me now." He ordered.

Shinobu at first hesitant, before pick up a small bottle from her pocket. "Here." She said while throwing it to Kai, who later received it.

"Thanks." He said before looking toward Sofia. "Be careful. This will be painful." He warned as he touches her right hand. He later uses his **Overhaul**, destroying Sofia's right hand. Using the bottle he received from Shinobu a moment ago, he take some blood before reconstruct Sofia's arm once again.

Sofia is awe by his Quirk. "You… You're human but why'd you possess **Blood Demon Arts**?" She asked in confusion.

"Not **Blood Demon Arts**. This is something that I got from since I was born." Kai replied.

"But still…. My right hand feel different than before." Sofia compliment his ability before giving a smile. "You're must be child that gifted by God." She said, revealed her faithfulness to Christian.

"Call me whatever you want." Kai replied while putting the bottle on his pocket. "Since it was impossible now to extract any information about Muzan, can you tell us exactly what happen during the time we come? Who is the boy named Rui is?"

Sofia then shaking for a moment, remembering Rui cruelty.

Kanae then decided to speak. "Seemingly, that young boy is doing something bad to you." She guessed.

Sofia later managed to stop her shaking, before taking a deep breath. "You're right Demon Slayer. Although I doubt you'll never try to understand us, seemingly there's no wrong to tell my story of how I'd end up being tortured by Rui." She said with sarcastic tone.

"Sofia…." Kanae speak once again. Her voice sounded sympathy for the female Oni.

"The reason is simple actually. This mountain is a natural barrier for Demon Slayer to enter. Ever since it was found out to be a conversation area of many species of spiders. That's why… Many weak Oni is gathering here, for protection against Demon Slayer as well to search for comrades." Sofia explained.

"Search for comrades…" Kanae uttered in disbelief. Oni should be having no care for each other except themselves. "Can those thing... Is possible? I mean, Muzan is keep watching your every movement..."

"Maybe the one that thinking like that only me actually." Sofia admitted, now her word is lost all of malice toward Kanae. "I… Actually being transformed into Oni around the time when Father Louis Frois come to Japan to meet with Nobunaga-sama, the one that become the Three Great Unifiers of Japan."

Kai slightly widen his eyes. Judging from her appearance, Sofia seemingly around fourteen to seventeen years old. She's being transformed since the end of Sengoku Period where Nobunaga already known as the 'Demon Lord'? So now she must be around four-hundred years old. "That means... You're not half-Japanese?"

"You… Come here at the same time as Louis Frois?" Kanae asked. She never expected this. Sofia is a true foreigner. Her reading of history surely help her this time. However, Oni with the age as old as her should be a member of Twelve Demon Moons already. Why'd she not?

"That's lie! No Oni other than Twelve Demon Moons is able to survive that long!" Shinobu retort.

Sofia nod. "Yes. Sorry for deceiving you earlier. Shion is the surname that I took from the couple of farmers that kindly take care of me when I'm still human." She apologized. She later look toward Shinobu. "And for you, it's your wish to believe me or not. But I swear to my God that I don't lie at all."

"Ugh." Shinobu grunted. "Fine. I'll believe you since you swear that way."

"Sorry Sofia. I truly confused now. If you truly already transformed that long, then why'd you able to survive this long? It is because of Muzan's influence then?" Kanae asked, clearly curious about her past.

"Probably yes." Sofia replied. "Anyway then, I'll tell you how this mountain is finally ruled by Rui."

**(Flashback – ** **Natagumo** ** Mountain; 5 Years Ago)**

Sofia is seen sitting on a tree while holding her cross necklace to praying. It's strange for an Oni to pray since she's a faithful God worshiper before become malevolence that can only consumed human.

She actually a young female from 16 th Century Portuguese that snick up on Louis Frois boat that sail toward Japan to run away from her abusive master and find her own freedom. After all, Portuguese and Spain at that time is still in a hot term after the Saragoza Treaty. When the ships already arrived in Japan, she quickly snick out from it and stays on the closest village and taken in by a kind couple of farmers, taking the surname Shion to blend into Japanese society. However, everything changed when she met Muzan Kibutsuji, who transform her into Oni due to she suddenly bumped into her and commenting how pale Muzan's skin is. She then never return to the couple, since she don't want them to sad that she becomes a Man-eating Monster.

Despite being transformed into an Oni, she later finds out that something strange happened since Muzan is transforming her. She finds out that unlike other Oni who immediately gone mad if they not consuming human flesh for few days, Sofia founds out that she somehow able to survive by eating wild animals such as apes, deer, boar, and the others. However, each fifty years, her Oni instincts is kicking out, forced her to eat human flesh by killing an unsuspected human who pass by. Since then, she tried her bests to keep hide from society by hiding on Natagumo Mountain, that revealed to be a perfect hiding place for her.

Maybe it's because she's a foreign since every Oni that she see so far is the Japanese so her blood have some cells to fight the malevolent man cells? But that's no matter now.

'My friend once said to me that freedom is exists out there. But, when I feel what's like to be free, someone is cursing me with this body. I know if I sane, I'll kill myself. But, God already give me this life. Doing something like that is only defied the fate that set by God.' She thought before she prayed using her cross necklace. "Oh God. Please… What shall I do?" She prayed.

She knows she herself is egoist to be alive till this time. But this is maybe her personality that was switch by Muzan, giving her the instincts to survive no matter what.

However, her safety on this mountain is over.

Suddenly, an Oni that had the appearance of a young boy is walking to her. He wearing the same outfit as her, a white kimono but his had a spider-web pattern on it. This Oni is Rui.

"Oh. So there's an Oni that already here?" The boy commented in neutral tone. "Perfect then."

Sofia is wary about this Oni. She then decided to act civil enough since her instincts didn't kick in now. She later jump down from tree she sit on. "Young boy, what business do you have here?" She asked.

"Don't ask like that." Rui replied with narrowed eyes. "Since now I'm the ruler of this mountain." He declared.

Sofia slightly widen her eyes. "And what did you mean by that?"

Rui is seen bored by Sofia question. "Just tell me. Do you want to be saved from those miserable Demon Slayer?" He asked with demanding tone. "If you want, become my family."

"Your… What?" Sofia asked, really confused. However, she stopped to act wary when she see something in the boy Oni's eyes.

Sadness and regret.

"How about it?" Rui asked once more. "If you don't want to, I can easily defeat you and hang you up until sunrise. Because-" He later revealed that his right eye had Kanji writing on it. "-a typical Oni like you have no chance against me."

'He's a member of Twelve Demon Moons! Twelve most Powerful Oni under the command of that man himself!?' Sofia thought in shocked. She never thought that a child like this is a member of the twelve strongest Oni.

How many humans that Rui eat exactly?

But, she can't let this boy wallowing in sadness. "Your eyes… seemingly yearn for something. Am I right?" She asked.

Rui nod. "A faithful family that'll protect me." He said. Although this actually meant that he want a underlings for his own personal gain.

"I'll accept." Sofia agreed. 'Somehow… Even if I only end up as his underlings, I want to fill the void on his eyes.'

"Welcome then." Rui later raise his hand. "From now on you're my family. Eldest Sister."

Sofia later receiving the handshake with no words.

"I actually want to transform you." Rui said. "However… Since your appearance is already like me and join me willingly, I'll give special treatment just for you."

* * *

After she joined Rui's 'family', Sofia finally get a glimpse of his cruelty. Ever since his first stay on the mountain, many Oni later gather since it was rumored to be a safe haven, only to face Rui and being forced to join his fake family or being hang up until sunrise is finishing the job.

However, Sofia never loathed Rui, even though she realized that the boy eyes become more ruled by his twisted personality. She knows that it was all thanks to Muzan, that some young boy become like this.

If she's never been turned into an Oni, she promised herself that Muzan Kibutsuji will get the punishment from God as hard as possible.

At one night, Sofia is seen walking around on the forest, when she's suddenly being hang up by strings.

"So… You tried to run away?" Rui then walking toward her while his other hand is holding a female spider that have many eggs that glued on her abdomen.

"N-no!" Sofia cried. "I… I just curious where'd you go. That's all."

Hearing that make Rui eyes slightly widen. "Is that so?" He said before releasing her from his strings. "Fine. This time I'll release you. But… Next time there will be no forgiveness."

Sofia fearfully nod before looking curious at spider on Rui's hand. "Y-you… Really like spider, don't you?"

Rui look at her and surprisingly nod. "They're just little creatures who did nothing wrong. Yet their number becomes dwindled. I come here in order to protect them." He said.

'Well, this is unexpected from a member of Twelve Demon Moons…' Sofia thought in confusion.

"What are you still doing here?" Rui asked with a little anger on his voice. "Go back before I'd changed my mind."

**(Timeskip – Few days before the main timeline)**

After five years have passed, Rui's fake family is growing considerably, consisting of Sofia and other eight Oni that he already forced to join. Different than Sofia though, most of them join Rui for their fear against the Demon Slayer or for their own personal gain by eating more humans to become strong enough to challenge Rui himself to become the new member of Twelve Demon Moons.

Sofia this time also befriend the Oni that posed as her mother, which having the actual appearance of female around seven to eight years old. She's the one that always defending her against Rui's cruel treatment and the other Oni who posed as Rui father, who starting to become more intense as time passed. She already concludes that Rui is different from what he is five years ago. So in this time, all she can do is look in pity when Rui pummeling her.

Recently, Rui is add the latest addition to his family, a female Oni that originally have the appearance of a young girl with black hair and slitted red cat-like eyes with black sclera and pale grayish skin. After Rui is altering her appearance using his blood, her appearance is almost the same as Sofia. Like the previous member, she doesn't remember her real name and Rui putting her on the position of Older Sister, a position below Sofia due to her willingness to join his fake family.

Sofia and the Older Sister are seen sitting on the up floor of the unused temple that set by Rui as their main base. From above, their see Rui is torturing Mother Spider, due to she's reverting back to her human form.

'Sorry. But… I don't know what I should do.' Sofia thought with regret because she's powerless and her Oni instinct to stay alive is always kick in.

"Eldest Sister." The Older Sister called her. "You worry about Mother?" She asked.

Sofia later look toward Older Sister. 'You must be being betrayed by the one that close to you and transformed like me.' Sofia thought in sympathy. "Hey, let's run away." She said.

"Run away?" Older Sister said in disbelieved.

Sofia later look at her with a kind smile. "I wouldn't say this to anyone but you. But you… Like Mother, is my friends. You seems not too consumed by this fake family."

Older Sister is shocked hearing it. "But… Is impossible…" She uttered.

Sofia shook her head. "It's not impossible. Tomorrow, Rui will be called by that man, and leave this mountain for a while. Let's us that chance to escape. If can, I'll ask Mother too."

Older Sister seems on thought for a moment, before she finally speaks up. "O-okay… I also… Don't want to live like this. I-I just want… To live without any disturbance." She agreed.

Sofia is smiled. "Okay. We're going to go tomorrow then."

**(Timeskip – Few Minutes before Kai's arrival)**

Sofia and Older Sister are seen running down the Natagumo Mountain toward the plains below. Like Sofia predicted, Rui is being summoned by Muzan for monthly report. Actually, Sofia also wants to ask Mother to run away as well but she's currently on a mission to look for food by Rui. Sofia become worried that Rui continuous hunts for human in the area will attract the attention of Demon Slayer to the mountain.

So instead, she first plan to escorting the Older Sister to the safety of a cave that she found on the plain below, and return tomorrow also bringing the Mother. But she never told them that she still want to stay here and still want to help Rui fill the void on his eyes.

"So… Running away I see?"

Sofia and Older Sister stopped when they saw Rui is blocking their way of escaping.

'I know that he called by that man, but… How'd he come back this fast!?' Sofia thought in disbelief. 'And his eyes. It's not the same as before… So, that man is giving him more of his blood, twisting his personality even more.'

"I actually never expected this from you, Eldest Sister." Rui said with a disappointment in his voice. "For five years… Now you want to run away from me?"

"I'm not running away Rui." Sofia said while she going into a battle stance. "I don't agree with the way you recruit your comrades for you sick cause. You just tortured Mother just because she accidentally reverts back to her actual form; you killed three of Oni you recruit himself just because they piss you off. I can't let the same thing also happen to her. So I will said it once, let us pass Rui."

"You failed to do your role." Rui said as he also prepared to summon his strings. "You really think you stand a chance against me?"

'I already learned your fighting moves and the timing you need to create the string from your hand.' Sofia thought. 'My **Blood Demon Arts** should be able to keep him at bay for a while even though he's one of Twelve Demon Moons.' "You! Quickly use this chance to-"

Sofia never expected as she suddenly being constrict by collections of web. Surprisingly, the one that doing it is the Older Sister. However, her face is shown regret and fear to what she's done.

'I-I'm sorry!' Older Sister thought in fear. 'B-but I…'

"So Older Sister is still sane." Rui commented while dispersing his thread. "Then, from now on you fit to replace her."

**(Flashback End)**

"That's all. The rest of the story is like the three of you saw. I was going to be hanged until sunrise, but then you guys save me." Sofia said, finishing her story.

"You… Willing to do that far…" Kanae commented after hearing Sofia's story. She know that all Oni have dark past that later Muzan's use to his advantage to transform them into his underling, but this? She's just gain her freedom from her Master and now she's being forced to obey to the more evil one? "I don't think Muzan is so despicable to turn you into Oni for petty reason. I'm truly sorry Sofia. I... Don't know if you're suffered that much."

"It's not your fault." Sofia assured. "I should be sorry for my harsh words earlier."

"But you're fool." Shinobu mock. "If Rui really fall that low… Why still you tried so hard to help him? It's just a waste of time."

"Because… I know what it feels to have a void in the heart." Sofia countered. "Like I said before, I was once a slave to a noble that I constantly being bullied by him just because my weak body. I see the darkness of humanity first-hand by that experience, and make me want to see the reason an individual doing something. Even if his treatment to his underlings is despicable, Rui is truly protecting this mountain from outsiders and he even sometimes let scientist entering the mountain to learn the spider in this mountain. Because of it, many spiders in here is very friendly toward Rui. And the most important is… How can I leave the friends that I created here behind? So you meant that I just run away and leaving them behind?"

"I still can't understand your mind." Shinobu said. "If I were you, I'll kill Rui and this Older Sister and saved only Mother."

"Sadly, you're not me." Sofia said. "I don't want to judge them just because their personality is twisted and their primal instincts is for eating your hypocritical kind."

Kanae later look at Kai. "Kai, what're you thought about all of this?" She asked.

Kai seems in thought for a moment. The information shared by Sofia surely will be useful. 'Protecting this mountain huh? Meaning that this Rui had complete control over all spiders here. If that so, He'll be wasted if just killed right away.' He thinks before look toward Sofia. "Sofia, since you're in here, I just go to the point. I'll go in here to build a base for my Yakuza group: Shie Hassaikai."

"Yakuza?" Sofia thought for a moment before nod. "I see. The groups that consisting of outcasts by society am I right? I sometimes pity them. This is not something that Nobunaga-sama wanted. The government surely changed then…"

"Your mountain seems to be the perfect base for me. Currently I only have two members: Kanae and Shinobu. But it seems I meet new member in here." He said. "How about it Sofia? Did you want to join me and being able to socialize again with the others without needing to hide yourself in here? Don't worry. I promised I won't do the same treatment as Rui." He offered.

Sofia is in silent for a moment, before nodding. "Deal." She said.

"My my…" Kanae commented not expecting Sofia is agreed to join that quick.

'So quick!' Shinobu surprised.

"But… I have something that I want, it's that okay?" Sofia asked.

"Since you tell us everything, that's fine. As long as it still fit our benefit." Kai agreed.

"Please… Don't kill Rui, Older Sister, and Mother. I know this sound foolish, but I believe that deep in his heart, Rui doesn't want any of this. His care for spider prove that he not lost his human personality completely. Mother and Older Sister is also my friend that I created while on there. I also can promise that their abilities will be useful for your Yakuza, Chisaki-sama." Sofia pleaded.

"But… Why'd Older Sister as well? If I not wrong, she betray you." Kanae asked. Why'd Sofia still want to forgive her even after what she's done?

"I know… That her expression during the time she binds me and Rui said he will burn me on the sunrise said… She feels sorry for what she's done. She only does that out of fear." Sofia reasoned.

"Okay then. Conditions accepted." Kai concluded. "But before that, did in this mountain there are some katana or **Nichirin katana** for these two?" He asked gesturing to Kanae and Shinobu.

"If I not wrong, we're close to the place where Rui's buried the **Nichirin katana** from the result of the last Demon Slayer attack on this mountain." Sofia informed. "It is located on the east two hundred meters from here."

"Thank you." Kai said before looking at his other members. "Kanae will escort me to there. Shinobu will stay here with Sofia. Can I trust you not to do any harm to her?"

"I don't know." Shinobu said with a smile.

Kai sighed. Surely Shinobu can never forgive Oni due to her past. "Protect Sofia body from any sunlight then. I'll open this dome entrance."

* * *

On the monk temple that used as Rui's base, the child Oni is seen sitting facing the Older Sister who lying on the floor while twitching.

"Congratulations Older Sister. For your efforts against Eldest Sister that time, I'll grant you more of my blood. I'm pretty sure your **Blood Demon Arts** will evolve further." Rui compliment her because she doing the role he give to her completely.

"Ugh… Uhuk…" Older Sister coughed before tried to stand up. "T-th…anks…"

"Now get out. I want to think of plan to capture Eldest Sister. Oh, and also calls Mother here." Rui ordered as the Older Sister is exiting his personal chamber. Once she's out, Rui sighed while lean back on already crack wall on the room. He then let a spider that hang on the wall is fall to his palm. "I know that she's already not fit the role that I gave her and thus fit to die. However… What's with this empty feeling?" He ask himself, never experiencing any of this ever since he becoming Oni.

* * *

On Older Sister side, she walk to the main room while being greeted by the remaining members of Rui's family.

The first is the combination of human head on a giant spider body. His face is similar to the Older sister demon and has the same facial features of red dots, pure white skin, and short white hair similar to Rui, with the only difference being that his eyes possess dark red, almost black Sclera with deep blue irises and pupils. This is the Oni that posed as Rui's Older Brother.

The second is a very muscular Oni. His skin was dark brown with the same red, dot-like design extending from his shoulders reaching down to his arms as other members of his family. He had long, pale white hair reaching down across his shoulders. His most unique trait was that his face resembled that of a gigantic spider with several eyes and spider pincers in both of his cheeks. This is the Oni that posed as Rui's Father.

The last is a female Oni with youthful appearance. A relatively short and voluptuous woman, she is similar in appearance to Rui, having the same milky-white skin, teal eyelashes and nails, and circular, red facial markings. Additionally, she had bushy eyebrows and long, white hair parted down the middle of her face which was tied with teal orbs into two, thick strands. She wore a lengthy, layered kimono — maroon on the inside layer and white on the outside layer — that exposed part of her chest and was tied with a patterned obi. She also donned a beaded necklace composed of teal and purple orbs and decorative anklets. She also goes barefoot and has black toenail polish. This is the Oni that posed as Rui's Mother, one of Sofia friends among Rui's family.

"Ki hi hi! So Rui's finally acknowledge you even though you're just a newbie." The Older Brother sarcastically said. "Splendid!"

The Father just grunted.

The Mother however, had a sad look on her face. She seemingly knows that Sofia is being targeted by Rui, but she feels relief that she is saved by someone.

"He said that all of you must work harder to meet his expectations." Older Sister replied. "Oh and mother, Rui want to see you."

"Okay." Mother replied before walking toward Rui's personal room. "Um… Daughter?"

Older Sister glanced to her.

"Did… She is…" Mother said fearfully, worried of Sofia's fate.

"She won't survive the sunlight." Older Sister stated as she walks away from the three members of her family. 'Sofia… I don't know what I do now. Please… Forgive me…'

* * *

Now back on the Natagumo Mountain, Kanae and Kai is walking to the direction that Sofia told them. However, the older Kocho seems now have some doubts of her resolve because of what Sofia said.

Is it true that not all Oni actually want to kill humans? Did some of them actually tried to hold herself from that like Sofia but eventually fail? How about her dreams? Did Sofia said to her actually true? If that so, what makes a Demon Slayer Corps other than a bunch of hypocrites that act on anger and revenge with the big reason for the greater good? Is it worthy to understand Oni further other than they're the scum of nature and Man-eating monster?

Kai seems notice this. "You seem worry about what she said to you." He remark. "It's all written in your expression."

"You're right." Kanae replied. "Ever since I met with Sofia… I began to doubt my dream? She's right after all. Why'd I have such dreams while I join Demon Slayer Corps who dedicated to purging Oni completely from this land? What if there's still Oni like Sofia out there, who being forced to transform without their own free will? If that so, what makes me no different than a hypocrites..."

"I'm not the type to judge people like Sofia, so I can't tell." Kai sighed. "However, when you said that you want to build a world where human and Oni can live in peace… You said it wholeheartedly, or just accidentally speaking?"

Kanae is silent for a moment, before she uttered. "O-of course… I do."

"If that so, then keep chasing that dream of yours. It's not like I said you shall forgive the sin they've committed, but it all based on your heart. Do something what you think is right. Don't ever being influenced by others if you want to chase your dream to become reality." Kai encouraged. "And like Sofia said before, to reach a dreams, sometimes you must sacrifice others..." 'Like what I did before.'

Kanae is swallowing Chisaki word very deep, until she's nod. "O-okay… Thanks Kai. I've feel a little relieved now." She thanked.

"I'm glad then." Kai commented in relief. He then see in front of them there's a grave that have two **Nichirin katana** is stabbed on it. "So this is the place."

"Seemingly." Kanae agreed while approaching the grave and pray for the deceased souls. "May all of you rest in peace in heaven. I promised as the Flower Pillar, I'll put an end to Rui's cruelty."

Kai however, is disinterested in praying since he never know them. However, he can't help but thought that maybe Oyakata-sama that Kanae mentioned is the same as Tomura. He Cared for his associates. This also extent to his followers as well.

After finishing her praying, Kanae later pull out two **Nichirin katana** that's available on the grave. "Luckily… One of them is also a special-modified **Nichirin katana**. Seemingly there are poison-user like Shinobu that's being killed. But, I doubt there's still poison remaining inside of it." She said after looking at one of the **Nichirin katana** that fit for Shinobu.

"Then our business in here is over. At least Shinobu have weapon to defend herself." Kai said. "Let's go back."

Kanae nod, look at him seriously. They later go back to the dome.

* * *

"I'm surprised there's also poison-user like me…" Shinobu commented as she received the **Nichirin katana** from her sister. Both Kanae and Kai already return to the dome.

Kanae nod. "I… Want to see it myself from the Oni in this mountain, Shinobu. I want to see… Is Oni is actually different than we thought they are?" She said with determination.

"Don't worry sister. You have my support. Your dream is good after all." Shinobu assured her.

"Thank you Shinobu." Kanae thanked. "By the way, did you and Sofia able to get along?" She asked.

"Why should I get along with scum of humanity like her?" Shinobu asked rudely.

"You should Shinobu." Kanae adviced. "If you can't, at least get along till' the raid of this mountain is completed. Can you do that?"

Shinobu is silent for a moment, before she nod. "F-Fine... I'll try..."

* * *

Later, the four of them are sitting in circle. Sofia is seen to be one that lead the raid toward Rui's base.

"Then let's begin." Sofia began. "Currently, including Rui and excluding me, the Spider Family, which that's Rui called is consists of five members. Each of them are more powerful than Mizunoto and probably can take on Pillar-level Demon Slayers if they're keep their guard down. So Kanae, even though you're Pillar, don't drop your guard when fighting them." She warned the Demon Slayer.

Kanae nod. "Thank you."

"Now let's begin with the introduction." Sofia said. "The first… Is the Mother Spider, the one that I befriend. Among us, she's the weakest and probably be deploy by Rui first. Her **Blood Demon Art**s allow her to created small spiders that will attach strings to her victim. Once get caught, she can manipulate the said person according to her will and the more you got closer, the stronger and more powerful her controlled victims be."

"A rather troublesome abilities indeed." Kai commented. "We still must worry about the spiders she created though."

"Then, I'll face her." Kanae said. "I know that you pleaded before to spare her. If that so… Let me do it."

"Fine. I'll keep your words." Sofia agreed. "The second is the Older Brother Spider, the most sadistic member of our groups that even more than Rui himself. He physically not strong and his speed is also not impressive, but his poison is the one that you must be careful of. It can turn someone into spider in just 30 minutes."

"If that so, I'll face him." Shinobu offered. "My speed is maybe enough to deal with him."

Sofia nod. "Then let's go to the Father Spider. He's the strongest among us and probably only rivaled by Rui himself. He's master at hand to hand combat and has incredibly tough skin. He'll be force to be reckoned with."

"My enemy then." Kai said. "I'll face him and after that… We'll just go to Rui right?"

Sofia shook her head. "There's still one more. Older Sister Spider… She's must being deployed as Rui last line of defense before he takes the matter to his own hands. I'll be the one that face her. She constantly under my watch since she first join thus I know her the most. After we beat these four, we can go to Rui. Rui ability is creating sharp strings that had the density of **Nichirin Katana**. It very sharp and as far as I know, no one is able to cut through the strings. However, I've never see him go all out so be careful."

"We will." Kai said.

"Okay." Kanae nod.

"No need to remind me." Shinobu said.

"Then, we will begin the assault on night." Sofia stated. "We will put an end to this cruelty."

* * *

Meanwhile, Rui is also holding a meeting in his base. Surprisingly, what Sofia predicted is true. He deployed Mother Spider on the front line, Older Brother Spider and Father Spider as the wall, and Older Sister Spider as his last line of defense before he's forced to take matter into his own hand.

"Now you understand your role perfectly. Our objective is two, we'll kill the three human that dares to disturbing our peaceful life and capture Eldest Sister for dare to defy her role. Understand?" He demanded.

The members of his family just simply nod.

"Very well then. Dismissed." Rui raise his hand as they come out, but not before he called someone. "Older Sister. Stay here."

The one that's called later turn to look at him. "What's the matter Rui?" She asked in fear.

"You must fit your role if somehow Eldest Sister come here. Can I trust you with that?" He demanded in threatening tone.

"O-okay Rui! I'm your Older Sister! I'll protect you!?" Older Sister said rapidly.

"Good." Rui said as he later look a spider that perch on his right shoulder. "Don't worry little creatures. I've promised once this matter is settled; the five of us will live as families and protect all of you from those despicable human. After all… No one is able to break our bond."

* * *

On the plains that's very close to Natagumo Mountain. The time already shown it was sunset. Someone is seen walking.

It is a young man around Kanae's age with black hair that tied into a bun and blue eyes. He wears a traditional blue kimono with black hand guards and over it, a black mantle. On his waist, a katana is seen sheathed completely.

The young man later sees the Natagumo Mountain from afar. "So that's Natagumo Mountain? I've never expected a group of Oni is resting there." He commented with a smile. "I wonder… Kanae, are you maybe on there purging Oni like your stupid organization ordered." He wondered as he continued walking to the direction of the mountain. "After all… My boss already give me order to kill… Every last Oni on there and used that mountain for our new base. All for the sake of reborn Juppongatana."

**Notes:**

**That's it for chapter 4! Sorry if they're no battle scene and just talk. The confrontation against Rui will be in the next chapter!**

**By the way, the Eldest Sister Spider Oni name: Sofia Shion (Original Name that I created) Mean 'White Wisdom'. I hope her name is reflect in her personality that don't want to judge other Oni from their twisted personality and sees them as humans that being manipulated by Muzan, although she maybe not sharing Tanjiro's swift death to Oni though.**

**Oh and since I said this is a triple Crossover of Boku no Hero Academia, Kimetsu no Yaiba, and Rurouni Kenshin, I plan to make some Rurouni Kenshin elements and characters being referenced or rather appears as an original characters that becomes practitioner user of the real Samurai X characters and from this one that I plan to make a rival Yakuza faction of Kai that consists of ronin and illegal sword-users: the reborn Juppongatana.**

**See you in the next chapter!**


	5. Chapter 5:Yearning

**/N: Boku no Hero Academia is written and illustrated by Kouhei Horikoshi. Kimetsu no Yaiba is written and illustrated by Koyoharu Goutoge. Rurouni Kenshin is written and illustrated by Nobuhiro Watsuki. I don't own the three of them.**

* * *

**How to read the story**

In the… – Normal

"You're…" – Conversation

'Why…' – Thought and telepathic communication

Kagune – Foreign words

"**Fired…"** – Deep Voice

**Tetsusaiga** – Technique, Quirk and special weapons

* * *

**Chapter 5**

**Yearning**

Night is finally arrived at Natagumo Mountain. On the old monk temple that being used as Rui's base, the member of Twelve Demon Moons is seen walking out from the temple. He then gaze at the night-sky.

"Time to finish this… And I'll live in peace with my family." Rui said with his calm tone.

* * *

On the other side, Kai deconstruct the rock dome that he created. The process is happen so fast that even make Sofia is gaping in awe.

"You're abilities are amazing. Maybe you already enough to challenge and defeat that man." Sofia said in amazement.

"You can say it like that. However, I still don't know about Muzan abilities yet, so I can't tell if this is useful against him unless I confront him face to face." Kai replied. "Let's go. We'll build a new base in here… With no fail."

* * *

Later, the four of them are walking to the direction of Rui's base as already being directed by Sofia. The three of them is wary of their surroundings, remembering Sofia explanation about each abilities of Rui's family.

Suddenly, Kanae unsheathed her new **Nichirin katana**, and sliced through the air, cutting something.

Kai later glanced toward her. "What's the matter?" He asked.

"I thought I see something…" Kanae said before seeing that what she cut is a spider webs. "A spider… Web?"

"This must be mother abilities!" Sofia warned. "Keep your guard!? Even only one string is already enough to-" Sofia unable to finish her words as she suddenly leap toward Kai and tried to slash him with her claws, only for him to block the attack using his right hand. The attack is scratching the right side of his forehead, since it was unprotected.

"Kai!" Kanae yelled in worry.

"Ugh… Even though I'd warned all of you…" Sofia said as her right hand suddenly moving on her own. "…To think that I've been controlled by the technique that I know…"

"You're too careless…" Kai commented plainly.

"But since when it happens?" Shinobu asked in confusion as she unsheathed her **Nichirin katana**. "Don't tell me… During the time my sister cut the web with her **Nichirin**!?"

"I see. So the spiders is jump to Sofia without we realizing it and now she's being controlled." Kanae analyzed. "Sofia. What range do you think that Mother Spider can control you?!" She asked in demanding tone.

"It's… About a half-kilometer…" Sofia said while struggling to gain control of her body. "But… Finding her is very hard. She… Is in safe place while controlling me…"

"I'll still go!" Kanae said to her. "Kai! Shinobu! Keep Sofia safe!" Kanae then leap to the tree and jump from one to another, trying to search the whereabouts of Mother Spider.

"Tch. It comes to this!" Kai later squat and put his hand to the ground, deconstruct it and releasing multiple sharp ground spikes toward Sofia. However, the controlled Oni is using her bare claws to break the spikes. "Hoo… You're not as weak as I thought you'd be." Kai compliment her.

"Ki hi hi hi!" Shinobu suddenly heard laughing sound behind her and see that Older Brother Spider is hanging upside-down from a tree using his strings. His cheek is seen puffed, ready to spitting something. '**Fukudo-tan!**" He then spit a purple liquid that heading straight toward Shinobu.

'When did he appear!?' Shinobu managed to escape using her agility, the poison is hit a tree, melting its wood. "You can erase your presence that easy I see." She deduced.

"Ki hi hi hi! A correct answer little girl!" Older Brother Spider sarcastically compliment his opponent analysis. "But… Need more than that to defeat me!" He said as he now spitting sticky webs toward Shinobu, who moved to the side to avoid it. "Ki hi hi! You can't escape that easily!" Older Brother Spider taunt as he spitting more webs.

"Now I see… Their strategy is to separate four of us or in this case, controlling four of us so they can have an easy fight. A simple but effective strategy indeed." Kai finally realized Rui's intentions. "However... He underestimated one thing. Our strength!" Kai dashed toward Sofia with the intention to destroy her body using **Overhaul**, so she will not be controlled again and construct her anew. Kai tried to touch her, but Sofia managed to evade the attack and deliver a kick toward Kai's forehead, making the Yakuza Wakagashira is dragged several meters. Kai later wiped the blood on his forehead. "Well… Not bad attack. However… Compare to Shinobu, Le Million, and that young boy… It's still nothing!" Kai later unleashed another barrage of ground spikes, however the spikes suddenly bending around Sofia's arm like a rope, restricting her movements. Glad that is the ground that he manipulated, so it more elastic and easy to control rather than rocks.

The controlled Sofia seemingly can't free herself. "Ugh… Well I've never thought you actually this strong. You actually… Can defeat Rui yourself if you want." She compliment him.

"Now silent for a while." Kai later swiped his finger on the strings that stiff behind her, destroying it completely. He later destroy the ground that bend Sofia, freeing her.

"Thank you… Chisaki-san… I've never thought I've been careless…" Sofia thanked.

"No need for that. Now I know what Rui's intentions. Despite being abusive like your claim, he strategies this battle well." Kai replied.

* * *

On the deeper part of the forest, Mother Spider is seen is controlling something with her threads, however, the threads later slacken. She widen her eyes on this.

'H-how!? My threads are broken! No! No! I don't want to face anymore punishment!' She thought in fear before sensing someone's coming closer. "Did I… Must use that?" She asked herself. "Yes! I'll use it!"

* * *

Meanwhile, Kanae is still jumping from tree to tree, looking for the location of Mother Spider judging by the thread direction.

"If she's a true puppeteer, she must be hiding on the undergrowth." Kanae said to herself as she still on the look.

Suddenly, a huge figure is appeared behind her, trying cut her horizontally using some kind of blade-shaped arm. Thanks to her sharp sense, she managed to avoid the attack by duck her body below the slash. She then jump to a close tree branch and turn around, only to shock by what she seeing.

"An… Oni… Without its head-on?" Kanae said in disbelief.

True. What Kanae currently face is a giant Oni body but without the head. There's also the threads that controlling it. His hand seemed modified to be like sharp appendages.

* * *

Mother Spider meanwhile is smiled evilly from her hiding place. "Now what will you do? No matter how skilled a Demon Slayer is, they still need to target the neck to kill an Oni. But this trump card of mine, **Ogre Marionette**, is from an Ogre Yokai that I unexpectedly found! It skin density is also thicker than Father! Now then, let see you can match it!"

* * *

On the other side of the battlefield, Shinobu still chases Older Brother Spider, who unexpectedly agile in moving from tree to tree. While keep his distance, he also spitting spider webs to entangled Shinobu with it.

'Ugh. There's no end to this! If the one that fight this Oni is Big Sister, she can defeat it quickly!' She thought in frustration.

"Ki hi hi! You're lured into a trap." Older Brother stated. "Take her down!"

Suddenly from above, numerous spiders are raining down toward Shinobu, who look up and gasp. She managed to avoid the rain of spiders in time by jumping from the tree she stood, but she failed to notice that a single spider is latch on her right shoulder and bites it. However, she didn't feel it.

"Ki hi hi hi! As expected from Tsuguko!" Older Brother compliment her. "But, you enter a dead zone! You can't avoid this in mid-air!" He then spits multiple webs toward Shinobu. But, he failed to realize that Shinobu is already prepared. **'Dance of the Butterfly: Frolic!'** She then delivering multiple stabs toward the webs barrage, make it fail to entangled her.

'What!? Using only multiple stabs she managed to destroy it! Now I see, what she stabs is the weak point of the webs… Tch!' The Older Brother thought in anger. "Then die! **Fukudo-tan**!" He then spits the venom toward Shinobu.

Shinobu widens her eyes seeing it. 'I can't avoid it!' She thought in panic.

**'Blood Demon Arts: Net-throwing Spider Web!'** A spider webs later entangled Shinobu and thrown her to the safety of the ground.

"That was close." Said the one that revealed to be Sofia with relief.

"Ugh. What an Oni-like way to save someone huh?" Shinobu ask with sarcastic tone while stand up. "I won't give you thanks."

"I'm not forcing it." Sofia replied.

"So… What happen to the one that managed to corner me?" Kai ask from behind Sofia. "Do you can't even bring down something like that?"

"Circumstances are different." Shinobu replied. "From his perch, he's practically untouched. To beat him, I must somehow get closer to him to delivering a fatal stab to his neck. However, that'll be hard because of the terrain that gives him the edge."

"The terrain huh? Then." Kai later put his hand on the ground, activating his **Overhaul **to sending a barrage of ground spikes toward the Older Brother.

'What! The grounds are heading toward me!? As if they have their own will!' He thought as he moves away from the stone spikes while it destroying the perch he's hiding. He then look toward Kai with angry expression. 'No Demon Slayers that can use such ability. What's with this bird-beak man! A runaway Oni!'

"You on the right zone that I want." Kai later sending another barrage of ground spikes toward the Older Brother, stabbing his abdomen and torso and pinning him to a tree.

'Ugh! I can't move!' The Older Brother grunted. 'Since I'm too focused on his attacks, I'm not aware of my surroundings!'

"Shinobu! Do it now!" Kai yelled.

"Right!" Shinobu later preparing a stance, before jump toward the location of the Older Brother and preparing a thrust. "This ends now! Dance of the Bee-" Shinobu momentum however stopped as she suddenly coughed blood and fall to the ground below.

"Shinobu-san!" Sofia yelled in worry.

"Ki hi hi hi! You bitten by one of my spiders don't you! Looks like the poison works faster due to you frail body! Ki hi hi hi hi hi!" The Older Brother laugh while taunting her at the same time.

However, much to his disbelief, Shinobu is doing some acrobatic movement in the air before landing softly on one of Kai's ground spikes that stab the Older Brother, before running toward him.

"What!? Impossible!" Older Brother yelled in fear. 'Why'd she's so agile after the poison entering her system!?'

"Regret your sins in hell!:** 'Dance of the Bee Sting: Mere Fluttering!'** Shinobu later delivering a powerful thrust toward the Older Brother's neck. The thrust so strong that it created a hole on the tree where he's pinned.

"Ahak!" The Older Brother cough blood while at the same time, veins starting to appear on his body. 'Impossible! I've being defeated… By a weakling like this!' He voiced his last thought as he later still have shock expression on his face, died at last because of the poison. His body keep pinned in the tree by the ground spikes.

"Uhuk!" Shinobu later cough some blood once more, while still in position of stabbing the Older Brother. "So… It still has some **Wisteria Poison** in it. I'm… Glad…" She said as she slowly lost her balance from the ground spikes and fall.

"Shinobu-san!" Sofia later utilizing her **Blood Demon Art** once again, catching Shinobu before she touched the ground and bring Kanae's younger sister close to her.

"Put her down Sofia. I'll heal her by separating the poison substance." Kai ordered as he prepared to using his Quirk toward Shinobu's body. "You did well. Shinobu."

* * *

On Kanae's side, she's still fighting with the headless Ogre. It proved much stronger than she thought.

However, that's all the strength it had.

'I'll cut those threads and the body!' '**Breath of Flower Fifth Form**…" Kanae later delivering nine consecutive attacks that cuts the threads as well as the Ogre's body to pieces. '**Peony of Futility**.' The Ogre later dissolves into ash after the attack.

* * *

Not far from there, Mother Spider is shocked to sensing that her threads that controlling the Ogre Yokai's body is becoming loose.

'I've beaten! My trump card is being beaten!' She thought in disbelieved and fear.

* * *

Back to Kanae, she later seeing the threads that lay on the ground and following the trail. 'If I follow this threads that still connected to her hands, she must be close by!' She thought as she keep following the trail.

'Even though that's my strongest move! I still being beaten! If it keep going like this! I will face that punishment again!' She thought in fear while cold sweat is seen clearly on her face. 'No! I don't want to face that kind of thing again! What shall I do!? What shall I do!?' She then gasp when she saw that Kanae is already close to her and **Nichirin Katana** in hand, seemingly ready to decapitate her head off.

'So this is the Mother Spider Oni! What Sofia said to me is right! Without her threads… She's powerless.' She thought as she keep running toward her.

'Oh no! I'll be killed! What shall I do now!?' She thought in panic when seeing Kanae before suddenly, she raised her hand and close her eyes. 'But… If I killed by her… I won't feel that kind of thing again… I'll free… And able to see her once again in hell… The only one besides the person that cherised me when I was a human...' She thought while remembering the day that Sofia always protecting her from Rui and Father Spider abuse. "Sofia…" She uttered.

Kanae widen her eyes seeing that Mother Spider seemingly give up to defend herself. She narrowed her eyes, remembering when Sofia explaining to her about Rui's cruelty. 'You must be sad. I pity on you…' She thought as she keep running and preparing to cut off her neck, only to stop her slash movement when the **Nichirin katana** is touching the soft skin of her neck.

Feeling the cold of **Nichirin Katana** on her neck, Mother Spider opening her eyes, only to see that Kanae is stopping her attack. She also had a pity look on her eyes. "Why…"

"I honestly don't know… Why did I not kill you… Although I know by the code of my organization that I must to..." Kanae replied, still focused the case Mother Spider made a tricky move. "I know that you're monster. You kill so much innocent people for live because you can't eat anything and sometimes for all of you entertainment. But… When I remember that all of you is human once before, I can't help to think the reason you choose to become an Oni: It is just because you want to, lost any will to live as a human, or being forced to become one… Like her."

Mother Spider does not believe what she heard. A Demon Slayer pitying Oni? She remember meeting various Demon Slayers like her and all of them is hating Oni with passion. But.. This one, who seemingly a Pillar.

She had such kind eyes. Like someone who cherished her as a human and Sofia.

"Although I know… Maybe what I did now is wrong… One of my recent comrades tells me, if you want to pursue a dream, you must keep that dream in heart and never being wavered even if that means your dreams is being mocked by someone. Or in my case, I must seeing the bigger picture." Kanae said. "You see… I have a dream to make a world where human and Oni can live in harmony with each other. But… That time I was too naïve. I only think the one that deserved forgiveness is Oni that never eat human. But… After hearing that many of you also being forced to be transformed into one, I evaluate my dream once again. And for that, I… Want to know more about all of you. Seeing you just give up easily… I can't bring myself to kill you. Even after I promised to Sofia-"

Hearing her friends' name make Mother Spider gasp. "Sofia!? You know her?! Where is she!? Don't tell me…"

Kanae later close her eyes and smiled. "Don't worry. She's alive. She's the one that ask me to spare you after all." Kanae kindly replied.

"I see…" Mother Spider later look down, tears slide from her eyes. "I'm glad… I want to meet her…"

"I know that she's the one that keep defending you from Rui's torture. Honestly, for a Demon Slayers like me, this is unexpected. I've never thought there are an Oni that cared for each other." Kanae said while cancelling her stance to kill the Mother Spider. "Then, will you help me to end all of this cruelty?"

Mother Spider later look toward Kanae while she's still crying. 'Her eyes. I don't know why, but during my time as a human… I remember that someone also give me that kind look. She's as kind-hearted as Sofia.' "I… Help you." She accepted. "So please… End all of this."

Kanae smiled hearing it while also helping her stand up. 'I did the right thing right? Sofia… You, I already fulfilled it.' However, she suddenly sensing something is raced toward her, and later trade the blows which revealed to be a katana. It was the same boy that's on the journey to Natagumo Mountain on the evening. Seeing Kanae able to block his attacks, he later jump forward to the ground and later inspecting his katana. "Heeh. For you to grow this strong. I'm impressed, Kanae."

"Who are you?" Kanae demanded to the mysterious young boy. She's wary of this mysterious newcomer. "State yourself. Your no a Demon Slayer, judging from your clothes."

Mother Spider just look toward the young boy, shaking in fear. 'I don't know why but… He has no killing intent on him.' "Be careful. I can feel… That he's strong." She warned.

"Ara. You forgot your neighbor." The boy later turn and look at her with a smile. "That's not kind you know."

Kanae later widens her eyes, seemingly shocked by the boy's face. "Y-Y-You're…"

"So you remember me after all…" The boy said in calm tone. "Hello Kanae. It's been a long seven years since we've last met."

"A-Ara-Arata…"

* * *

On Kai's side, Shinobu is finally healed from her poisoning after Kai's using **Overhaul**. The latter now is healthy than usual since Kai also strengthen her muscle a bit.

"I relied on you once again…" Shinobu lamented while at the same time feeling weak because she always need her sister and Kai to save her again.

"Don't think too much about it." Kai replied. "Then Sofia, I suggest with this, the one that's left only Father, Older Sister, and Rui am I right?"

Sofia nod. "We're now close to Rui's base. Let's go." She said as they walk once more to Rui's location.

Shinobu then look up toward the sky. "Big Sister, you must catch up to us soon."

* * *

Back on Kanae, she never expected that she seeing him again after a long seven years.

Arata Eiji. She always remembering him as her close neighbor and sometimes he visit her house since her parents and him are having close relationship. However, during the Oni attacks that killed her parents, she heard that he and his families are moving to the city, since Arata's father is got a new job in there.

"It's been a long seven years isn't it? Kanae." Arata keep smiling like usual. "Did you enjoy your life now killing Oni left and right? Oh and how's your sister doing now?"

"I-I hear that you and your parents is going to city seven years ago." Kanae said still in disbelief seeing her childhood friends. "But… How'd you-"

"I… Have my own ways to know your job right now." Arata said with a smile. "But, don't think bad of me okay? Since my boss ordering me to slaughter any living Oni or person on this mountain." He then brandishing his katana, which outing an intimidating aura.

"I-impossible. That katana… Is one of the legendary katana…" Mother Spider revealed while shaking in fear. "He's dangerous!"

"Oh? I can't believe an Oni is able to guess my **Suijingiri Kanemitsu** perfectly. As I suspect from a being that lived for hundreds of years." Arata compliment her.

"A-actually I…" The Mother Spider stuttered.

"So Kanae, before this turn bloody, I give some conditions." Arata said toward Kanae. "I give you chance to get away from this mountain along with your companion here. I still respect you as my childhood friend so…"

However, Kanae sensing that he's not the same Arata as before. But at the same time, she can't feel his killing intent. "I won't. My friends are still here. There's no way I'll leave them." She said as she preparing her stance. "And besides, what business you want in here anyway?"

Arata then sighed. "Very well then. If you die, don't blame me." He said as he suddenly sheathed his **Suijingiri Kanemitsu** back and entering stance of battoujutsu.

"Arata please. I don't want to hurt you." Kanae pleaded.

"But you are entering a stance that's ready to fight me. So your plead is fall into deaf-ear." Arata replied her pleading harshly. "Anyway… You really think you can defeat me? Just because you're breath-user."

Kanae later run toward Arata, preparing to attack him. 'He come with a intent I'm pretty sure. But at the same time, I can't feel anything from him. In any case, I'll just injure him with the back of my katana.' '**Breath of Flower Fourth Form: Crimson ****Hanagoromo**!' She then delivering a single slash that twists and curves toward Arata. However, before it can reach him, he suddenly vanish. 'He's gone!'

"So that's **Breath of Flower** I heard so much about?" Kanae gasp and look that Arata is seen perching on a tree behind her. "Not bad. Since I heard that you're the one that created it." He compliments her.

'B-but how!? That kind of speed he utilized!? Is the same as breath-user and Oni!' She thought in surprise.

"Heeh. So you want to analyze me. Then, I'll not waste time anymore." Arata said as he suddenly disappear from the tree.

Kanae tried to looking for his whereabouts.

"Behind you!" Mother Spider yelled. She's already keeping her distance since the battle began.

Kanae later turn quickly and true to what she said, Arata is already behind him, ready to slash her sideways. But Kanae later delivering a counter-attack that parried the attack, but Arata once again is disappear from sight. 'He's fast and maneuverable! It's the same-class as the **Thunder Breathing**!'

"You need to get serious Kanae." Arata said as he now sitting on a rock in front of her. "With such speed, you can never beat me." He then seeing the sky. "Well, I can't go with this battle forever. Let's finish this shall we?" He then jump down from the rocks. "As a special gift, I'll present to you: One of my technique." He then entering the stance of battoujutsu once again.

"Arata…" Kanae later entering battle stance as well.

"Here I come." Arata said as he suddenly disappear from his standing place.

'Oh no!" '**Breath of Flower Second Form: Honorable Shadow Plum!**' She said prepared to do rotating swords slashes. Suddenly, Arata reach close to her with hand on his **Suijingiri Kanemitsu**. However, Arata later pass through her and when he did, a part of Kanae's left shoulder is being slash heavily. 'Ugh! He got me! If I not releasing Second Form in time, my neck is already severed by now!' She thought while gripping her injured shoulder with her other hand, making her **Nichirin katana** clatter on the ground.

However, Arata right shoulder also being injured as well, although more lightly. "So you can avoid my iaido. Impressive if I must say. However, the willingness of our sword is what makes it different. Your sword have no desire to kill." He then turn to face his childhood friend. "Say Kanae, did you want to join me?"

"What?" Kanae turn to him. "What do you mean?"

"Join me and my groups, because our ultimate goal is to get rid of Muzan Kibutsuji and later, Ubuyashiki family. After that, we can take our time to take-over this country and built a better one." Arata said.

"Take-over… A coup?" Kanae uttered. "And you targeting… Oyakata-sama? So that means… You're against us?!"

"Oh. It seems I talk too much." Arata said while rubbing his head.

"Arata." A voice is called from a tree behind him. He then turn to look at the mysterious person that's revealed to be a young man with an average build and short, spiky black hair. He had noticeably small, rounded eyebrows and two prominent scars on his left cheek. He's wearing the same outfit as Arata.

"Masachika-san. I wonder why you would follow me up here. Master told me to do this alone you see." Arata greet his seemingly allies.

"Masachika…. Kumeno…" Kanae is once again is shocked. Masachika Kumeno is a close friend to Sanemi Shinazugawa, a fellow Pillar like her. He's deeply affected by his death and once blamed Oyakata-sama for being useless and weak as hell. So how'd he's still alive and well?

"Change of Plans. We can leave this mountain for later picking. You're called by Master for another task." Masachika explained before look toward Kanae. "And… Also spare all of Oni in here. That's what he ordered."

"I see. After all, Master is know what's best." Arata said as he walks away from the scene. He then stop for a while. "Kanae. If you want to join our underground organization, the reborn Juppongatana, the door will always be open for you and Shinobu. After all, It is better you know as soon as possible… The reason of why Demon Slayer Corps is born besides the noble goal of exterminating Oni from Japan."

"Arata." Masachika called.

"Alright. Alright." Arata replied. "So then goodbye Kanae. Give my regards to Shinobu-chan as well." He said as he used his super speed to jump to the tree where Masachika is.

Masachika later look at Kanae. "It's nice to meet you again. Kanae Kocho the Flower Pillar. Tell Sanemi… That he shouldn't worry about me anymore." He greeted.

"Wait-"

But when she's about to give a chase, both Arata and Masachika are long gone. "The Demon Slayer Corps other reason… What does he meant by that?" 'And Juppongatana…? Isn't that the name of famous rebels group during the Meiji Era from what father use to tell?'

"Um…" Mother Spider shyly called her. "I'm sorry for not helping out there."

"Don't worry. I'm fine really-Ugh." Kanae grunted as the wound is itching in pain.

"Your wounds!" Mother Spider later run toward her and preparing her threads. "I'll stitch it!" She offered.

"Thank you…" Kanae thanked. "But… Do that for later. For now, we must focus on bringing Rui down." She then remembering something. "Um… Anyway what's your name? I'm Kanae Kocho."

"My name?" Mother Spider thought for a moment. "I… Don't have one. My memories as a human… Are foggy. But I remember... Someone called me... Aiya."

"Aiya... I see." Kanae said. "That's a good name."

The Mother Spider, now known as Aiya feels something that she never felt after she became an Oni. Embarrassment.

"Um… I…" She said shyly.

Kanae sighed. Seems she must help her build her confidence then. 'Sofia, I already keep my promise. Please, defeat Rui quickly!'

* * *

On his base, Rui is seen sitting when he suddenly stand up. "So… Mother and Older Brother have lost huh? Well… Both of them can't do their role perfectly." He commented with little attachment before return inside the base while Older Sister is standing. "Sister."

"Y-yes!?"

"I expect you to work your role perfectly. If no, you know what'll happen right?" Rui asked.

"Y-Yes! Don't worry Rui I'll do it!?" Older Sister answered in fear.

* * *

Back to Kai, he along with Sofia and Shinobu are still walking toward Rui's base. Previously they already defeated Older Brother Spider.

Kai suddenly stopped walking. "It seems they're here." He said.

Suddenly, from a tree behind him, Father Spider jumps down with both of his hand form a fist. "STAY AWAY FROM MY FAMILY!?" He said in loud tone.

"To loud." Kai turn behind to face the Father Spider.

Shinobu know what Kai will do. 'Fighting him at close range will be your funeral.' She thought.

Still not knowing his ability to the fullest, Sofia yelled in worry. "Chisaki-san! Avoid it!"

But true to what Shinobu thought, Kai simply duck the first fist make by Father Spider. After that, he swiping his right hand across Father Spider's torso activating his **Overhaul**. The Father Spider's body soon inflates and then exploded, leaving only his lower half that falls to the ground. A shower of blood also falls to the ground.

Sofia looks in amazement to Kai's Quirk. "Im-Impossible. Father Spider is the strongest member besides Rui. But… He killed him with one attack." She said in awe. However, her awe later turn into confusion as Kai later cleaning the blood from his jacket.

"Tch. This is why I still hate the aftermath." Kai said while cleaning his jacket. "Anyway, that's take care of him. I presume he's the one who throw that rock when I meet Sofia that morning." He deduced.

However, Shinobu later widen her eyes. "Chisaki! Stay away! It will regenerate!" She warned.

"He won't." Kai assured. "What I destroyed is his upper-half in molecular level. He won't be able to regenerate I can promise you that."

"Molecular… Level? Is that such thing is possible… With that power of yours?" Shinobu unable to put in her mind how powerful Kai abilities are. His Quirk make him deadly adversary in close-range combat. One touch from those deadly hands mean instant death if he wish so. He can solo all Pillars in hand to hand combat if he wish so.

'Besides, when I killed that Oni in the city, I realized something. Oni regeneration is actually simple. They have special cells in their body for regenerate on every parts of their body. I think the reason why **Nichirin katana** can kill Oniby cutting the neck is because it was the center of all Oni's body system and their core is in there. However… Since that core and the regeneration cell is only on cellular level and my Quirk can destroy to molecular level and anything that touch by it can't regenerate or fix itself unless I wish for it, what I need to do is just to destroy that regenerate-type cells. They then render immobile and as good as dead.' He analyzed. 'That means I somehow become a wildcard against them huh?'

"Chisaki-san,The base is already close. Let's go." Sofia said.

"Yes. I won't waste any more time in here." Kai replied as he turned toward Shinobu and Sofia, continuing their journey to Rui's base.

* * *

On the base, Rui widen his eyes, sensing that Father Spider is being killed. "Impossible… He's the one that fit the role. His strength only behind me. Yet he is beaten with one attack?" He asked while vein starting to appear on his head. "Damn those humans." He then stand up and walk outside the temple. He actually don't want to go this far, but it seems it's the time to take matter to his own hand. "I'll personally cut you to shreds. Bird-beak."

* * *

Meanwhile, Kai, Shinobu, and Sofia finally arrived at the temple that's becoming Rui's base. The temple condition of being damaged and the other damage to it make Kai sighed.

"Seemingly, it needs some cleaning from contamination." Kai commented.

"My estate is still cleaner than this." Shinobu commented.

"Well… We only use this building to run away during sunrise that's all." Sofia reasoned.

"So… You came at last Eldest Sister." Greet a feminine voice that's revealed to be Older Sister Spider who walks from inside the temple. "I see you allied yourself with these humans."

"So… You finally appear after all of the other is defeated… Haruki." Sofia greeted.

'Sofia… Please just turn around and get away from here! I really don't want to hurt you again!' Older Sister, now known as Haruki thought in worry. "I give you one last warning Eldest Sister. Stay away from this family." She said.

"This is no family. I know you're realized it do you Haruki?" Sofia reasoned. "True family is build on trust and love, not through fear like this. Rui concept of family is wrong."

"Talk all you want." Haruki dismissed the argument. "I wonder Eldest Sister, can you fight me now? After I receive more blood from Rui." She then suddenly dash toward Sofia tried to punch her. Sofia managed to block the punch though.

"Chisaki-san! Shinobu! Go without me! I guarantee that Rui is inside!?" She yelled before jump backward and firing her **Blood Demon Art** toward Haruki, who surprisingly managed to dodge it. 'She's not as fast as this before!'

"You seemingly weak now… Eldest Sister." Haruki later delivering roundhouse kick toward Sofia, make her thrown to the bushes that close to the temple.

* * *

On Kai side, both he and Shinobu is finally entering the main hall of the temple. On the center of it, Rui is seen standing, his face is neutral as usual.

"Shinobu, keep guard outside. You recently healed injuries only become hindrance." Kai said.

Shinobu nod, before turn around and walking outside.

Rui however, suddenly tried to slice Shinobu using his strings, but Kai using his Quirk make collections of wood spikes that entangled the strings.

"You surely a brat." Kai mocked.

"And you dare to disturb my peaceful life in here." Rui return the mockery.

For a while, both of them releasing a heavy killing intent, making the air around the main hall becoming heavy and the air seemingly clash with one another.

* * *

Even Shinobu, who managed to reach outside the main hall by now, feeling this monstrous air. 'Such killing intent. Both of them are truly monster!' She thought. 'However… Compare to Rui, Chisaki killing intent is heavier! How can that be!?' "I'm... Dared facing this monster..."

* * *

Rui himself also feel slightly intimidated by Kai's killing intent. 'This Bird-beak, I don't know why. But… His killing intent is immense. Almost reach the same level as him.' He thought.

However, Kai suddenly releasing all of his killing intent, before looking toward Rui. "I take it that you're Rui… The ruler of this mountain?"

Rui however didn't answer.

'I take that as a yes then.' Kai deduced. "You know what? Since I'm not Demon Slayer, I had no intentions to slay you at all. After all, they're just a bunch of sick people."

"This is interesting." Rui finally replied. "I never thought there are human who despise them so much. However, you disturbing the peaceful life of me and my family. There's no forgiveness."

"Then tell me. How can you called they your family if you controlled them through fear? It's all nothing but delusional bond." Kai mocked Rui so-called family groups.

This however triggering Rui's anger. "What did you just say?" He asked in menacing tone.

"Hah. Did you hearing is mute or something?" Kai sarcastically asked. The response he got is collection of sharp strings is racing toward him. Using his **Overhaul**, Kai manage to deconstruct all of the strings before it can cut him into pieces. "You really never hearing person speak don't you? I wonder if that coward Muzan is also the same."

Hearing his master being mocked make Rui become angrier. "You dare said his name so casually?"

"What's wrong with that? A coward like him doesn't deserve to lead an organization or something." Kai continuing to mock Muzan cowardice.

"Then cut into little pieces." Rui later sending five sharp strings from his right hand toward Kai, who jump to avoid the slash. It managed to create a huge slash mark on the floor.

'For a string, that surely great destructive power. This kid had some talent to use it. Just like Sofia said, he's too useful to be killed.' Kai thought before landing on the ground and sending barrage of wood spikes toward Rui.

'Now I see. All of your annoying power comes from your arms. If that arm is cut…' Rui later creating formation of strings on both of his palm before shooting it toward Kai.

'Like I'll let you!' Kai is already prepared. Touching one of the wood spikes, he deconstruct it before making a rising platform, making the strings only cut the platform instead. "You know brat, I like you power! How about we chat for a while!"

"Chat or not. Not you to decide. **Blood Demon Arts**-" Rui later make pointing his right index finger toward Kai. "**Tamaito**!" He later shoots a string bullet toward Kai, who managed to avoid it by moving his head to the left. Kai later countering by sending barrage of wood spikes that racing toward him. The momentum now is so fast that make even Rui couldn't prepare his strings on time. He then jump upward to avoid the stone spikes. However, he's exactly in the position that Kai wanted him be. Sending more wood spikes, it later managed to pin Rui, stabbing both of his arms and legs, pinning him to the roof of the temple. "Ugh. So that's what he's aim for. I never suspected the speed of his attack to form would be this fast…" He uttered.

"So… Have enough?" Kai asked casually while looking at him. "I just want to talk and you're the one who taking the first move."

"What? To spare me because of Eldest Sister request? No need to pity me." Rui replied. "She's failed to do her role. She's nothing but useless for me."

"Oh I see. Then what's you lead is no family at all huh?" Kai mocked. "More like a mafia. But in case of the boss, all that he cared is about your own safety."

This however make Rui grit his teeth in anger. "You surely not know who's you're dealing with." He stated.

"What?"

"You think you can defeat me… One of the Twelve Demon Moons…" A wind later pass by, blew off the hair that obscured Rui's right eye, revealing his rank as Lower Moon Five. "…You make me laugh!" He later creating strings on his hand, cutting off the restraint.

"So… A true member of Twelve Demon Moons. However, you just the second weakest. What do you have in mind that you stand any chance against me?" Kai taunted him.

"Shut your mouth it's annoying." Rui replied the mockery as his arm suddenly turning blood red. "Do you really think… That my string is that weak?" He later is doing slashing movement toward Kai.

'His strings is turning red!?' Kai thought in disbelief before avoid the attack by squat below it. 'Its power is clearly different from the last time!'

"Well now… Where's your cocky attitude. Or… You want to take back your words of saying that my bond is fake?" Rui taunt. "Let me stated one thing. You can't beat me. After I beat you… He will make me stronger than now."

* * *

Back to Sofia, she still fighting against Haruki. Seemingly even after Rui is busy battling Kai, Haruki still not back down. She likes being afraid of something.

'Rui's influence already this far!' Sofia thought as she shooting another sticky webs only for Haruki to counter using her webs. "Haruki please! This battle has no meaning at all! I know you didn't want any of this!"

Haruki grit her teeth. Sofia words surely got to the point. "Shut up!" She later shooting another torrents of webs toward Sofia. "You know nothing about me! Rui's the one who accept me and recognize my strength! I don't need any friends!"

"But your face is telling different!" Sofia countered as she avoiding the webs. "You just act in fear of Rui while in truth… You're your own person! Think for yourself Haruki! What's you truly want!"

"You know nothing about me I say!" Haruki later run toward Sofia, claws ready to slash her. Sofia also countered with her claws, creating little spark when they claw is meet with each other. 'Please Sofia! Just give up!' She thought in concern.

"No need… To hide yourself!" Sofia later using the momentum of the sparks to punch Haruki's face, making her skidding on the ground before she jumping to the ait.

"Tch, in that case, now I'll kill you! **Blood Demon Arts**." She later shooting torrent of webs at such speed that even Sofia is shocked by it.

'Such Speed!' Sofia only managed to see the attack as the webs later covered her body in form of ball.

"**Acid Cocoon**." Haruki later jump back to the ground, before walking toward the web ball. "You just stay in there until you're melting because of the acid."

"Acid?" Haruki widen her eyes as her **Blood Demon Arts** is being destroyed. It is later revealed that Sofia is elongating her claws to slash through the webs. "There's none inside of it. As I suspect."

"But how!? I should be stronger than you now!" Haruki said in disbelief.

"Didn't I tell you before? You didn't want any of this. And if you do truly want to kill me, I maybe already melt inside." Sofia replied calmly. She later is brandishing her claws. "Let's finish this Haruki."

"Grrgh…." Haruki later elongating her claws as well. "Sofia!" She yelling at her before dash toward her.

Sofia later does the same, and the two later meet on a clash. However, Sofia is proving faster than Shiro and stabbing her stomach.

"Ugh!" Haruki coughed blood.

"I inject paralyzing venom to your body. Even an Oni will not be able to move in an hour." Sofia stated.

"Ugh… Sofia… I'm sorry…" Haruki uttered before the paralyzing venom take effect on her body, making her unconscious.

Sofia later softly strokes her head. "No need to worry Haruki. I already forgive you ever since I know you." She later look toward the sky, showing the sky that turn brighter every second. "The time… Is already morning. The time is getting thin... I hope Kai already defeated Rui."

* * *

Meanwhile, Kanae and Aiya are still running toward the direction of Rui's temple before Aiya suddenly reverting to her true form: a much smaller, childlike body compared to her previous, more voluptuous figure. Her skin was marked with two maroon lines on each of her cheeks and her eyes were rounder with yellow irises and x-shaped pupils. She also wore her short, black hair parted to the side with bangs framing her face and two, low pigtails.

Kanae who seeing it, quickly hold Aiya before she fell due to decrease in size. "So… This is your true form?" She asked while continuing her running.

"Um… Y-yes…" Aiya said in fear, afraid that Kanae will torture her like Rui did.

"Don't worry. I think… You true form is cute." Kanae assured her.

"Y-you t-t-think s-so?" Aiya asked.

Kanae nod to assure her she's need no fear because of suddenly transforming to her true form. However, she later seeing the sky. "It's… Almost sunrise… We must hurry reaching the temple." She uttered. 'Kai, Shinobu, Sofia. Please be safe!'

* * *

Inside the main hall of the temple, Kai is still busy fighting Rui, who become more serious after releasing his true power as Lower Moon Five. Kai already have some shallow slash wound on various parts of his body and outfit.

"Ugh." Kai grunted as he deconstructs his right arm that's fatally injured then heal it again. "I see now. The true power of your strings is blood huh?"

Rui unexpectedly smiled. "Oh… You're one of the few persons who found out my **Blood Demon Arts** secret."

"It all clear now. You created those strings using your fingernails. Since it also not human fingernail, no wonder it so sharp. And… for the reason your strings turn more powerful after pumping your own blood into it it's because it had special properties in it. Am I right?" Kai analyzed each of Rui abilities.

'This man. He's able to know my abilities that fast. He's dangerous. Better eliminate him right now.' Rui thought in wariness. "Then as a prize, I'll kill you with one of my special moves." He later swing both of his hands backward. '**Blood Demon Art: ****Kokushiro**!'

Around Kai, formed a cage of strings that red in color. "Hmm… This is…"

"To honor your intelligence, I'll kill you quickly. Goodbye." Rui said before waving his hand once again, causing the cage to shrinks with the intention to cut Kai to pieces.

"You're underestimate me." Kai simply said as he later swing both of his arms to the directions of the web cage, making it inflate before being exploded. However, not only the cage that's being destroyed.

Both of Rui's arm also exploded because the strength of **Overhaul**. "B-but H-how…" 'All my strings didn't reach him at all. He cut all of it, my strongest one! To think he's able to move his arm in a very fast time. I let my guard down!' He thought in frustration.

"Now, gladly talk with me brat." Kai said as he later approaching him.

"You're underestimate me. I can regen-" Rui however turn his expression to shock. 'What!? My arm won't regenerate!' He thought.

"Try it if you can. I already know the secret behind your regeneration. All of you Oni have special regeneration cell on every parts of your body. It quite ingenious method though. Because of it, everyone including Demon Slayer thought your kind is some of immortal being." Kai revealed his knowledge. "However… Facing against me who's studying cells, molecules, and DNA for years is your doom Lower Moon Five, Rui."

Rui now grit his teeth in anger. Without his arms, he won't be able to utilize any special moves of his **Blood Demon Art**.

"Seemingly your **Blood Demon Art** factor is from your arm. Without that, you're just a weak, useless Oni." Kai mocked. "Now, if you just act civilized like people and talk I probably considering to return one of yours."

"Like I said." Rui suddenly unleashing strings from his left leg. "I'm the one that decided that!" He then kick toward Kai, making the sharp strings is heading toward him.

'What!?' He thought in surprise as he using his **Overhaul**. However, the strings surprisingly cut Kai's left arm and mask, but the **Overhaul **is still a success. This time, all of Rui's body except for the head and neck is explode.

"Grrgh." Rui grump as his head is rolling on the ground.

"Ugh… I'm surprised that you can use your foot-nail to unleash those strings. Make me dropping my guard there. Damn… You make me breathing the air of filth." Kai said while grunting in pain because of his severed left arm. "But…" He later uses his **Overhaul** on his severed arm, deconstructing it before restoring it to normal. "It still not enough." He later walk toward the severed head of Lower Moon Five. After close enough, he stomps on Rui's head using his left foot. "Now… Care to listen brat?"

"I'll kill you." Rui replied in anger.

At the same time, Kanae along with Aiya who's already in her true form is entering the temple hall. Both of them are shocked by the carnage of the battle and the fact that Kai's defeated Lower Moon Five easily like most Pillar did.

"Rui… Is…" Aiya utter in disbelief. She never believing her tormentor is reduced to head and now at the mercy of Kai.

"Kai… You defeated him." Kanae said while looking something obvious. "Your mask…"

"Thanks to this brat." Kai replied while looking toward Kanae. "I guess you're already meet with Shinobu and Sofia out there? By the way, who's that brat with you?"

Kanae however, didn't answer immediately. Her heart is beat faster after seeing the scene in front of her. 'Without his mask on, K-Kai… Is surely handsome…' She thought in embarrassment before shaking her head to make those thought go away. "I already meet them. Sofia already defeated the Older Sister. And this girl with me is Aiya, the one that posed as Rui's mother."

"I see." Kai commented simply.

"So you failed your role as a mother huh?" Rui severed head later talking with intense killing intent toward Aiya. "As I expect… In the end, all of you no fit your role-"

"Silence." Kai ordered as he pressed more on Rui severed head. "Role? What you're leading exactly? Yakuza? Thugs? Mafia? Obviously not like family."

"Don't compare our bonds to scum like them!" Rui replied. "We're tied together by strong bonds of family. More than just friends!"

"You call that torture is family bond!?" Aiya suddenly shouted. "Even I'm an Oni, I know that family bond isn't like what you do to us!"

"You're silence! Failed mother!" Rui roared in anger, making Pereira shriek and shaking in fear.

"So what Sofia said is right." Kanae remark before walking toward Rui and later squat to look at him. "Your eyes…. So sad and filled with regret. You must be having a sad life when you're human."

"Heh. This is new. What Demon Slayer do pitying Oni? Don't you think we're animal?" Rui asked with venom on his voice.

Kanae shook her head. "For most including me, yes. You're monster that killed hundreds of human. But…" Kanae later touch Rui's cheek. "I know that you're protecting and befriending all spiders in this mountain so they're not facing any threats from outsider. How can I call that kind thing a monstrous act?"

"Silence! What did you know!?" Rui asked in anger, before a tear suddenly rolled down from one of his eyes. "This… Feeling…" Rui uttered, before his mind is suddenly flashback to something unexpected.

His life as a human.

**(Flashback – Mid-Meiji Period)**

Rui is seen playing with a spider on the yard in front of his house. Winter already passes, and it's currently spring.

'So fragile little creatures. Yet… Others just stomp on you while they're playing with no care.' Rui thought in sympathy for the spider. "I wonder… If little creatures like you can talk like us human. Maybe I can enjoy myself despite my weak body."

"Rui!" Called a young woman from inside the house who gasps by what she saw. "Rui! Don't play with spiders! They're venomous! Put it down!"

"But mo-"

"Didn't doctor told you you can't go out for a long time?" His mother remind him.

Rui, being a kind child obeyed his mother. He then put the spider on a rock. "Let's talk again tomorrow."

* * *

However, Rui's body is got worsen to the point he can't go out from the house and stay on bed. He doesn't want this because he didn't want to be a burden to his parents.

When suddenly, a young male around thirty years old while wearing extravagant outfit of the government is entering his room. The most distinguishing features is his plum red eyes.

"I feel sorry for you. Let me help you." The man said with clearly no care tone.

This is how Rui is turn into an Oni by Muzan Kibutsuji.

* * *

Since he turn into an Oni, Rui's parents are not happy. Despite becoming healthy, he now can never walk on daylight and must eat human flesh to survive. That proven when Rui is killing a man for him to eat, horrified his parents. Then at one night, his parents tried to kill him. On act of defense, Rui is killing both of them and feeling something is snap inside of him.

He feel that the bond he had with his biological parents is fake. He once heard a story about a father that died saving his son from a river and was touched by it. But, he deduce that his bond currently is not real.

How want he is, for a true bond.

Suddenly, he heard that his mother said sorry because give him a weak body.

That make Rui once again question his mindset. He also remember that his dad also want to bear his sin for eating people.

Then he realized… He cut his own true bonds with his own hand by killing his parents. However, thanks to Muzan, he always considers the bond is a lie.

All except one.

After Muzan encourage him, he left with wonder how strong Rui will become.

'Lord Muzan is true. My bond is nothing but fake and it can be received through fear. But.' He then look toward Spider that exist on his yard. It seen capturing an insect on his web and feeding it to her young. "For little creatures such as you, I guess I can trust that all of you make a true bond for me. I'll search for a paradise where human scum won't reach so I can protect all of you."

**(Flashback End)**

'So… That's it. All that I wanted so far… I understand that I'm wrong; I can't bring myself to the truth… I love both of them every day. Although I already built a fake family to fill my heart… The sadness won't stop. Even if I befriend those little creatures… It can never erase my guilt. My memories as a human disappear when I become stronger. And because I'm the strongest… They only afraid of me. What that man said is true. What I'm lead… No different than a group of thugs. I foolishly… Want a bond that I can't never get anymore…' He thought while tears are starting rolling down from his eyes.

"From what I see you remembering your memories as a human…" Kai commented before suddenly stomping harder to Rui's head. "… Then what's that face mean? Where's the brat from earlier huh?"

"Kai. Please don't. Don't you see-"

"I see what I see Kanae. The face of someone that says telling die is the best atonement for me." Kai replied with harsh tone. "You see brat… Don't you think you just fit to die after remembering something so pitiful like that. You're now no different than villains! In fact both of Demon Slayer and Oni. They're villains!" Kai yelled. "Why'd everyone in here think death is the best atonement huh? Death is just cowardly act to run away from your sins when still alive!"

Rui just look toward Kai. "But… I killed hundreds of humans… I can't go… To the same place as them…" He said with his human personality return. "Hell... Is only the place of me..."

"If I must say, what'd you do is fixing your wrong thinking it while you're still alive now. Going to heaven or hell based on you because it just a metaphor and believe of each religion of humanity." Kai said. "However, because you already a villain, I expected you entering group of villains as well."

Aiya not believing what she just heard. "Mr. Kai… D-did you…"

"Join me, Rui of Twelve Demon Moons." Kai offered. "You're not fit to just die in a place like this. I can guarantee that you're free to do things with your spiders in here with the exchange… I'll take over this mountain and you tried to move on and started do something to repent with less evil ways." Kai later look toward Aiya. "For a start, maybe you can have a bond and care for your groups that you make during your time as an Oni."

'Care… For them?' Rui thought when he see something.

Kanae, Aiya, and Kai also seeing something unusual.

Suddenly, hundreds of spiders is walking toward Rui severed head. They're stopping few meters from Aiya, Kanae, Kai, and Rui.

"All of them… This is spider from the temple…." Aiya uttered.

Kai have no comment about it.

"All of them… Seemingly sad because… We took Rui down." Kanae said in sympathy. "He's really good in taking care of them."

"All of you…" Rui said in disbelief when all of the spiders are like crying by rubbing their heads using their front-legs. "I see… So all of you really cared for me that much…"

Kai, seeing it as non-aggressive act, pull up his left foot from Rui's head. "So how about it. You'll join me or not? If you worried about Muzan-"

"I don't care anymore." Rui replied. "Like you said, I'm already a villain that should not be forgiven. But… Seeing them crying because I want to die… Is more evil."

"I see." Kai later touch Rui's head, using his **Overhaul** and restoring his body but not forgetting to destroy the regeneration cell on his body. "I like those words."

Rui later sit up. "Fine. I'll join your groups. As a way to walk out from my already villainous path. This mountain is yours to own. Do as you want." He said.

"Thanks for the consideration." Kai replied.

"Chisaki." Shinobu called him by entering the temple hall. Beside her, Sofia is seen carrying Haruki who still immobilized. "So it's over…"

"You can say so, and we got four new members it seems." Kai replied.

Sofia later put Haruki on the floor, before walking toward Rui who's sitting while being watched by hundreds of spiders. "Rui…"

"Eldest Sister…" Rui uttered while look at her.

Sofia later smiled. "So… You finally let out all of it. I'm glad, Rui."

Rui unexpectedly smiled. :Forgive me... For not realizing the entire time. You determine to stay with me... Despite my endless tortures to you."

Sofia shook her head. "I'm already forgive you Rui."

"I don't know why… I feel sorry for him…" Kanae said with sadness on her voice seeing Rui.

"He just wanted love and true family. That's easy enough." Kai said to her. "His desire… I can understand it clearly." 'After all, in my time… Case like this is happen every time.' "Anyway, this temple needs some maintenance. Is dirty as hell."

And so, at last Kai got a base for his new Shie Hassaikai. The Raid of Natagumo Mountain end at precisely 06.00 A.M. But by defeating Twelve Demon Moons, he's already thrown into a conflict of Oni and Demon Slayer.

* * *

On the **Dimensional Infinite Fortress**, Muzan is sensing it.

Rui is being defeated and gained his memories as a human. And what's more, he join a group called Yakuza? Those groups of filthy outcasts?

How want he to detonate his cells immediately by himself but he find that somehow he can't.

This starting to annoy him. From Rui cells, he can describe the man as tall with black hair. But the strangest thing is the plague mask.

"Who is this man that dares to defy my authority?" Muzan uttered with clear anger on his voice. "Nakime."

Nakime took the form of a pale woman with a grayish complexion, who had sharp, blue-stained nails and notably red lips which sharply contrasted the tone of her skin. She had shiny, waist-length hair of a dark brown color, which she wore falling down her back in slight waves that cut off sharply at the ends, with two chin-length strands left to frame her face and long bangs that obscured her eye set in between them, swept to either side of her nose. She wore a plain black kimono with a white lining, secured with a striped pale brown-striped obi, white socks and no shoes. She was always seen holding a wooden biwa.

She nods as she knows already what Muzan is wanted. He then playing her biwa.

Suddenly in front of Muzan, an Oni is appeared. He was a man of average stature who had pale, grayish-white skin, with what appeared to be three large, cross-shaped scars cut into his cheeks and the center of his forehead and noticeably elf-like, pointed ears. His eyes were wide and sharp with orange irises, the kanji for Lower Moon Three etched into his left, as well as short, black hair and a widow's peak. His outfit consists of a dotted, bamboo-colored yukata with a pinstripe pattern, a piece of dark cloth around his waist, and a lighter one around his neck, as well as two golden hoop earrings on each ear and a pair of wooden sandals with black straps.

"Wakuraba." Muzan addressed his Lower Moon Three.

The Lower Moon Three, now known as Wakuraba, immediately kneeling in respect and fear of Muzan. "How shall I serve you?" He asked.

"I believe you already know that Rui is defeated few hours ago." Muzan said.

"Yes-"

"I'm not finished talking fool." Muzan said with anger. "I want you to go to Natagumo Mountain and kill him and the remaining survivors of his foolish family. And… If you can kill a tall man with black hair and wearing plague mask, I personally allow you to challenge one of the Upper Moons. Is my order clear?" He demanded.

"Yes! I'll do it after the sun is set!" Wakuraba replied in loyalty.

"Good." Muzan is happy hearing it before Nakime strings her biwa, making the Lower Moon Three is disappearing from the scene.

No matter what, this man must die.

**Notes:**

**And That's finishing this very long chapter to close the clash on Natagumo Mountain Arc. For the mysterious reborn Juppongatana will be explained in few chapters to come. The next chapter will be a fight against Wakuraba but more talking and daily activity, as it will involved Kai's groups is cleaning up the temple and planning to build an underground base for Shie Hassaikai, and a certain leader of Demon Slayer Corps beginning to worry about his 'children' disappearance.**

**For one that doesn't know Masachika Kumeno, he's the old friend of the Wind Pillar, Sanemi Shinazugawa who in Canon died fighting against Lower Moon One. In my story, I'll explain the reason why'd he survived in many chapters to come.**

**In this story, I want to make other Lower Moons beside Rui and Kyogai getting more spotlight than they used to be. I'm disappointed that Muzan just dispatch all of them in manga and anime because they're weak. I think his anger only the best trademark of him. Why not he realizes that he can use them to prolong time? Don't worry though, the other Demon Slayers, Tanjiro and Co. and the Upper Moons will appear, though not this time.**

**See you in the next update. By the way, this is the name meaning of Original names:**

**Aiya: Bright Silk**  
**Haruki: Springtime Tree**  
**Arata Eiji: Fresh Prosperity**


	6. Chapter 6:I Curse My Weakness

**/N: Boku no Hero Academia is written and illustrated by Kouhei Horikoshi. Kimetsu no Yaiba is written and illustrated by Koyoharu Goutoge. Rurouni Kenshin is written and illustrated by Nobuhiro Watsuki. I don't own the three of them.**

* * *

**How to read the story**

In the… – Normal

"You're…" – Conversation

'Why…' – Thought and telepathic communication

Kagune – Foreign words

"**Fired…"** – Deep Voice

**Tetsusaiga** – Technique, Quirk and special weapons

* * *

**Chapter 6**

**I Cursed My Weakness**

It's been a few hours since Kai is take over the Natagumo Mountain from Lower Moon Five, Rui. Now, he takes the business that he very hated of.

Cleaning the filth. On in other words, fixing the temple for his new base.

Although not only Kai, the remaining members of the Spider Family, including Rui are cleaning up the temple on the interior part. Since they can't touch the sunlight, Kai order them to do so, while he, Kanae, and Shinobu cleaning the outside.

On Kai side, he creates broom sticks from the wood of the trees using his Quirk, then giving it to the others. He also creates feather dusters from the birds around to clean up the dust. "I never expected that I use my Quirk to creating something like this." Kai uttered. He usually more like to use his deadly Quirk in battle and experimenting with Eri.

"Don't utter like that Kai." Kanae said from the entrance of the temple, cleaning it. "If that so… Your abilities are really useful."

"For a household that is." Shinobu joked while sweeping the floor on the outside of the temple.

"Did they in the inside are doing their job?" Kai asked.

"They doing fine really. Although they… As expect of Oni, can't walk out from the temple during the day." Shinobu informed.

"Though I really wonder… Did Kanao is well on the estate along with the others?" Kanae suddenly mumbled with a little sad tone. She truly miss her home.

"Your estate you say?" Rui asked while walking from inside the temple while holding a feather dusters on his right hand. He stopped just a few meters from the entrance, so the sunlight won't reach him. "So the rumor that Demon Slayer Corps is rich are right huh?"

"Yes. Shinobu and I are own an estate called the Butterfly Estate. It's our personal home and we also have some orphans in there… Well, many of them because of evil Oni…" Kanae replied. "But I not mean you and your family Rui."

Rui silent for a moment. "If that so, I suggest you treasure them dearly Demon Slayer." He replied. "Don't ever turn to be like me."

"And you eat your own words." Shinobu commented.

"Rui, I suggest that you already finish cleaning up the temple?" Kai asked the former owner of the mountain.

"Still on-going." Rui replied. "I'm just curious with the work on the outside."

"Well then you finish the inside right now." Kai ordered. "Before noon, this base must be clean from filth."

Rui nod, before going back inside the temple.

Kai sighed, wondering how long he and the others are finished on cleaning the temple.

* * *

Meanwhile on the room inside the temple, Sofia not join the cleaning. She's watch over Haruki, who still unconscious because of her poison. Since she's still not known of the outcome of the battle, Sofia suggests to Kai that she watch over her to explain everything. Currently, only Rui and Aiya doing their job on cleaning the temple.

"Sofia." Aiya called her. "Why'd you not clean the temple? Chisaki-sama will be mad at you if you don't." She said. Despite a little confident now, the trauma of being tortured by Rui still not missing.

"Don't worry Pereira. I already ask for his permission. I'll clean the temple after Haruki is awake I promise." She assured her.

"Okay then. I hope Haruki is awake soon. Because… Even though Rui is now changed…" Aiya uttered, afraid to say that she still not comfortable staying with Rui.

"No need to afraid of him Aiya. I'm pretty sure Rui is different than what he used to be." Sofia assured her.

"O-o-okay. If y-you say so…" Aiya is stutter to agree before continuing on cleaning the temple.

At the same time, Haruki is groaning while opening her eyes. She then immediately sit up with cold sweat all over her face. She then looks at her surroundings. 'This is… Inside the base!?'

Sofia smiled seeing her friend is awake. "So you're awake Haruki."

"Sofia! What're you doing here!?" Haruki yelled in fear. "I-if Rui k-know…"

"Then I'll punish you?" Rui said while entering the room. "There's no more of that. I already realized that my treatment to all of you is wrong. I already apologize toward Mother and Eldest Sister. Because of that-" Rui surprisingly bow in attempt to beg of forgiveness. "Forgive me for ever said cruel things to you Elder Sister. I finally realized what I want is just people that cared for me like my true parents. I was ruled by that selfish desire for a long time."

Haruki can't say any words by what she saw. Here in front of her, the one that always act monotone, cruel, and cocky toward her is bow for forgiveness. "I… Don't know…"

"Haruki…" Sofia uttered, understanding Haruki confusion. "No need to worry. Rui is changed from before."

"Please… Leave me alone for a while." Haruki pleaded. "I… Still need to think about many things…."

Sofia at first insisted that she shall accompany her, but she finally accept Haruki pleading, and she and Rui later go to the main hall of the temple.

After both of them gone, Haruki later weep herself using her sleeve. She still feel guilty for betraying Sofia while she helps her to escape Rui's wrath, yet she's still smiled at her.

The same for Rui. Why'd her tormentor and boss now act very differently?

And why'd she's still allowed to live, after doing betrayal one after another?

For now, she must let all of the thought out before she's ready to received what'd actually happen.

* * *

Meanwhile, far away from the Natagumo Mountain. On somewhere, lies a massive estate that's revealed to be the headquarters of the Demon Slayer Corps.

In the terrace of the estate that's facing a beautiful garden; a man is seen sitting with a soft smile on his face. He has light skin and black shoulder length hair. He has something like a mark that is caused by a poison that also makes his skin look as if it was rotting spreading down his face and covering one of his eyes making him partially blind. He wears a black kimono with a long white kimono jacket with a pink and purple mist like pattern that starts around the lower back/waist.

On the garden that faces his sight, a young man is seen bow in respect. He is a tall, muscular, and slender man with spiky white hair and large eyes. His face and body are covered with scars, accrued over his many years of fighting demons. He wears a standard Demon Slayer Uniform with white haori. The young men then spoke. "Oyakata-sama, thank you for giving some of you busy time to hear my request. I hope you always in good health." He said in respectful tone.

The man, Kagaya Ubuyashiki, also known as Oyakata-sama or in other words Kanae's leader is nod with a smile. "It's okay Sanemi. All of you is like my children like I always said, so I always spare my time." He replied kindly.

"Oyakata-sama, you must be have the same worry as I did. For five days, both Kanae and Shinobu are not returned from their mission to investigate the district that is suspected hiding one of the Twelve Demon Moons." The young man known as Sanemi begin his speak.

"I understand why you would worry Sanemi. I also not receiving any news because their Kasugai Crow is also not seen coming here. Young Aoi and the others at the Butterfly Estate also have the same worry for them. I tried my best to comfort them, but… I cannot lie that I'm worried about their well-being." Oyakata-sama said in sad tone.

"I have my personal gratitude toward Kanae Kocho. If not because of her, I maybe still look at you with the same disdain look Oyakata-sama." Sanemi said.

"I understand Sanemi. I'm sorry for not being a leader of this organization like you expect me to be." Oyakata-sama said apologetically.

"The main is, I want to request something Oyakata-sama." Sanemi finally said his request. "Please Oyakata-sama, allow me to go to the district where Kanae Kocho and Shinobu Kocho. I ready to face a hard fact. If they somehow still alive, I'll bring them to here, so the girls in the Butterfly Estate can be happy again."

"Are you sure you'll be alright Sanemi? It's not that I not trust your ability. There's a big chance they encounter an Upper Moon. I'm afraid something will happen to you." Oyakata-sama said.

"Don't worry Oyakata-sama." Sanemi said while looking at him with a smile. "I become the Wind Pillar is because of your kindness. Because of it, I'll never disgrace the title you gave me."

Oyakata-sama later nod. "Very well Sanemi. If that's you wanted, I'll allow you to go there alone to check the condition. I can only pray for your safety on there."

"Don't worry. I promise I'll bring both Kanae Kocho and Shinobu Kocho safely." Sanemi promised.

* * *

Now we go to the Butterfly Estate. It is the personal house for Kanae and Shinobu since they're joining the Demon Slayer Corps. Since that, both of them also picks up some girls that the parents are killed by Oni, making them as their students or doing the daily household activities.

On the backyard, a young girl is seen busy drying clothes. She has deep blue eyes that fade to a lighter blue at the bottom, along with white pupils, straight black hair with a parted fringe, and twin-tails. She wears two blue butterfly clips to keep her twin-tails in place. For her outfit, she wears the standard uniform with the addition of a white nurse dress on top of it. Her uniform is tinted slightly blue. This girl is Aoi Kanzaki, a caretaker on the Butterfly Estate.

Ever since Kanae and Shinobu disappearance due to Kai forced invitation to join him, the Butterfly Estate turn somber. Aoi is seen with a frown like usual, but her eyes is showing sadness, because the fate of the two is still mysterious.

Meanwhile on the house terrace that facing the backyard; another young girl is watching Aoi. She has large, gentle eyes of a pink-lilac color that are framed by thick eyelashes. She has thin black hair, worn tied into a ponytail on the right side of her head and fastened by a pink and green butterfly ornament. She has a straight fringe and two loose, chin-length strands that curve downwards from above each of her ears. For outfit, she's wearing pink kimono. This is Kanao Tsuyuri, the adopted youngest sister of Kanae and Shinobu.

Kanao then flip a coin to the air and catch it with the back of her hand, showing head. She then speak toward Aoi. "Aoi, you can rest if you want." She said.

Aoi later look toward Kanao. "No Kanao-sama. Since Kanae-sama and Shinobu-sama still not return, I must keep the house clean enough, so they can rest inside a clean house."

Kanao just smiled hearing it, although it because she can't decide how to reply that.

From the side of the room, three little girls watching Kanao and Aoi with sad look on their face.

The first is Sumi Nakahara. She has light skin and a set of black, button-like eyes. She wears her hair in low twin-tails fastened with blue butterfly clips. She sports a long-sleeved nurse uniform tied with a blue ribbon around her waist and wears white socks and shoes. "Kanao-sama and Aoi-sama surely sad. Just like us." She said.

The second is Kiyo Terauchi. She is a girl with light skin and a set of circular, black eyes. She has shoulder-length black hair with thin bangs framing her face, along with two pink butterfly clips on each side of her head. She wears a long, white nurse dress tied with a dark, reddish-pink bow around her waist. She also sports white socks and shoes. "It's been five days since Kanae-sama and Shinobu-sama are gone on a mission. Yet they're no news. I'm afraid something bad happening to them." She said.

The third and the last is Naho Takada. Naho is a light-skinned, young girl with button-like black eyes. Her hair is parted in the middle with two braided twin-tails tied with green butterfly clips. She wears a long-sleeved nurse uniform with a green wrap tied into a bow around her waist and white socks and shoes. "Me too. I hope they're safe wherever they be." She said.

* * *

However, true to what they predicted, on Rui's temple in Natagumo Mountain, Kanae is sitting on the terrace of the temple while having sad look on her face. It's almost close to six days since she along with Shinobu leaves on their supposed mission to locate the hiding location of an Upper Moon Oni. Although she know his identity goes by the name Douma.

But now, she and Shinobu are under thumbs of someone else. But, despite seemingly lack of concern he display for them, Kai truly take care of them greatly till now.

Besides, he's the one who saving her life and because of that, making Shinobu away from path of vengeance that will happened if she died.

'I know that Kai have a dream of making his destroyed Yakuza being established again. I and Shinobu already promised to join him with the promise that he shall never tell the Emperor Taisho about the existence of Demon Slayer Corps. He knows that I and Shinobu will leave after he's completing his goal. But… After seeing Arata that night, why'd his words keep ringing on my head?' She thought wallowing in her own mind. "Arata… What truly happen to you during all these years?" She uttered.

"Lady Demon Slayer." Kanae look behind her to see Rui is calling her from a spot where sunlight won't reach. "Can I talk for a while? It's personal." He said.

"O-okay." Kanae replied while walking inside the temple where Rui is seen sitting. She then sit facing him. "What're going to talk about Rui?"

"I just want to thank you for what you did during that time lady. Because of you, I finally regain my memories and finally understand what I desperately want. Your kind words also help me to fix my relationship with them." Rui thanked her, referring to his created family.

Kanae nod. "You know Rui, I want to ask you something, since you a member of Twelve Demon Moons and…"

"I know." Rui cut off. "Lady, you have a fine dream indeed. It's pretty rare for human to take pity to Oni, since even Demon Slayer Corps, including Pillars saw us as monster with no redeeming qualities. It's hard to find human with the dream such as you."

"I-I see. Thank you then." Kanae thanked. "It's because… I feel pity for you. You're formerly human. All of you who turn into man-eating monster because of Muzan twisted words. You're pitiful creatures, but monster at the same time that actually should not be forgiven at all, maybe that's how I think at first." She replied. "But... Sofia's word seemingly open my eyes a little about not caring about anyone's opinion when pursuing a dream."

"I see. I understand that I'm monster that already killed hundreds, maybe even thousands. Even so, Kai-san still forgive me and all the spiders in here love me." Rui admitted. "For someone who tried forgiving us is absurd. But even though now I should be in hell, Kai-san give me a chance to repent from my twisted way to the less twisted way…"

Kanae then decided to change the topic of conversation. "Um Rui… I know this maybe sound personal but… When you'd change into an Oni?" She asked.

"I… Changed into one… During the Meiji Period." Rui revealed.

'During Meiji!? And he already become Lower Moon Five!?' Kanae thought in surprise. If someone who transform from Meiji Era can already become a Lower Moon Five. What-if someone transformed into an Oni during Sengoku Period?

She can't imagine how powerful that Oni can be, since on that time it's a matter of life and death, not peaceful enough like now during Taisho.

However, one thought suddenly crossed to her mind. 'Wait a minute! During Meiji!? That means-' "Rui, I want to ask you something."

Rui raise his eye. "Go on. As long it doesn't concern that man, my body is safe." He said.

"Do you know… About a rebel group… called Juppongatana?" She asked.

Rui then narrow his eyes. "Why'd you ask that?"

"I… Just curious…" Kanae hastily replied, hiding her encounter with Arata and Masachika. "I know very little about them except my parents once told me that Juppongatana was a group of rebels that plan to overthrow Meiji Era. Since you lived during Meiji Era, can you tell me a little about them?"

Rui later silent for a moment, before speak. "I know about them. Although only in general. Did you not mind about that? Because I have some personal experience with one of them." He asked.

Kanaed nod seriously.

"Very well then." Rui replied. "From that man perspective, it is a group of twelve elite fighters, although some of them not fighter at all. Each of them are considered to be master of each their own sword, both literally or not and from what officially said in the newspaper, aiming to overthrow Meiji government and change it to their own image. The one that same as Bakumatsu time that is." He explained. "From what's written, they've been nightmare for at least ten years."

"Do you know any specific information about their member?" Kanae asked.

"Unfortunately no. Despite they sometimes hunt Oni as a mercenary or clash with the Demon Slayer Corps, I know not much. When I become an Oni, that man also brief about them for a while, but he not put them as a threat, since that man feels it just a human matter. But surprisingly, each of them doesn't use any kind of breath styles when fighting us." Rui replied. "However, with one of them, I never forget one scene. During that time, before I and my family moving to city, the previous village that I stayed was slain by one man for his own pleasure. He has the appearance of a man around his 40s, wearing some strange outfit with eye-pattern on it. But the most distinguishing feature is that he's wearing a blindfold with strange kanji on it and have some kind of spear with iron ball at the other tip. On his back, he also carries a turtle shell." Rui tell his encounter with one of the Juppongatana when he's still human.

"Such violence…" Kanae said with disgust for this man. "How could a human... Do such kind of thing to other humans?"

"Maybe it's not thing I should say, but human not always a saint and social creatures like you always taught in the Demon Slayer Corps. They also have monster of their own right like that man who did that to my previous village. It just… Humanity is blind at their own darkness and instead blaming all of fault to us Oni. Because like you said before, we're the true personification of human dark personality and blaming us is easier than humans." Rui said. "Although it's also not a wrong thing for blaming us."

"Thank you Rui." Kanae thanked him.

"There's no need to thank evil such as me." Rui denied the thanks before standing up. "I suggest you shall see Mr. Kai now. Seemingly he has something to talk with you personally." He informed.

"With me?"

* * *

"So there are underground base in here as well?" Kai asked Sofia who's standing beside him. Currently, he's checking the interior of the temple after all of Spider Family already cleaning it.

"Well… Although it's very messy down there, due we only using that to hide if the sunlight are penetrating this temple." Sofia replied while making a small laugh.

"It's not time to laugh, that means you and the others must clean it. All of the tools are already exist." Kai said in disappointment.

"Okay okay." Sofia said before walking into the underground base to clean it.

Kai sighed. Ever since his plague mask is destroyed by Rui, he never ever consider to repair it although he can do it easily. He doesn't know why he won't repair it. His heart didn't understand why he's doing it.

'Maybe I just put that off, to sever my connection from that filth world, and focusing on pursuing the debt of me to Pops.' He concluded. "Besides, the air in here are still fresh enough to breath in…"

"Kai. Did you call for me?" Kanae finally appear in front of door of the room that connected to the underground base.

"Perfect timing Kanae." Kai greet her. "Let just talk somewhere else. Sofia is still busy cleaning the temple."

* * *

Both of them later go to the terrace of the temple and sitting on there. The two silent for a moment, before Kai is speaking. "Kanae. Do you and Shinobu… Miss your home on your organization?" He asked.

Kanae widen her eyes. Of the entire thing he can asking for, he ask this? "Why… Did you ask something like this?"

"I… Just pity you a bit. Seemingly… You have very important person on there, I understand it clearly, in there one of them must be trying to pay the debt of you taking them in." Kai reasoned.

"I see." Kanae said. "But… Are you not afraid that I or Shinobu will betray you for this?"

"It's not." Kai later placed one of his hand on Kanae shoulder. "For Shinobu I don't know. However… I trust you."

"Kai…" Kanae not expecting why Kai would trust her even though know her only few days. "Okay then. If you allow it, tomorrow I along with Shinobu will go to the Butterfly Estate for a while. I promise I'll return after few days."

"Okay then." Kai said. "Did I need to escort you?"

Kanae shook her head. "You recently got new members. Why don't you tried to tighten your bonds with them? You already know us enough."

Kai sighed before stand up and turn back to the temple. But, he then stop midway. "Kanae, if you have any free time…. Escort me to your estate. I… Curious if there can be use as a temporary base or there are skilled person enough for my partner in lab." He said before walking inside. "Just don't die during your way to your house okay, or I lose valuable assets to Shie Hassaikai."

Kanae smile while nodding. "Don't worry Kai. I promise that I'll return here."

* * *

"And that's how the situation currently right now." Shinobu is explaining everything toward Haruki, who's still in confusion with what happen. Although she actually didn't want to, Kanae advised her to get closer to the others.

"I see. So in other words, Rui's losing his hold on the mountain…" Haruki utter. "That's hard believe. To think a human other than Demon Slayer Pillars can defeat one of the Twelve Demon Moons by himself."

"Then, if you already understand everything, I'll go outside for a while." Shinobu then stand up before walking outside. 'Honestly… Demon Slayers talking and even must befriend Oni… What am I thinking?' She thought to herself as she walking on the temple corridor.

* * *

The time later shows sunset, meaning the situation will become tense. Kai already concluded that since Rui is seemingly Muzan valuable assets, he must be sending some assassin to punish him for his betrayal or the worst scenario is targeting Kai himself to take his head as a trophy.

The Wakagashira is seen sitting on the outside, watching as the sun goes down. Day switch to Night. "The air surely feels not right." He commented. "I wonder Muzan Kibutsuji… Will you keep wasting your underlings or you will show yourself in front of me? Show me your worth as the Ruler of the Night." He challenged.

* * *

At night, Kanae and Shinobu are seen sitting together on a bedroom that prepared by Sofia. Currently Kanae is telling Shinobu of her encounter with their long lost neighbor and Masachika, also about the Juppongatana.

"Arata… Is join with the underground and planned to assassinate Oyakata-sama and take over Japan to built a new one? And… Juppongatana?" Shinobu not believe one bit that her older sister told her. Of course like Kanae, she knows very little about Juppongatana except from what their parents told. Hearing it send shivers to her spine, since she's been told how cruel a member of Juppongatana could be. "C'mon Big Sis… That group is destroyed. That's not possible if a fanatic exists. This time is not Meiji anymore." She said.

"Maybe not. But… This situation is dire Shinobu. They're targeting Muzan like us, but I don't know for whatever reason, they targeting Oyakata-sama. This is bad Shinobu, we must warn the others about this condition." Kanae said. "That means, in any time we must be prepared if they're attacking our base."

"But sister… Our code doesn't allow us to harm other besides Oni." Shinobu said.

"Didn't you break that code when you're attack Kai? It's forbid to pointing your **Nichirin katana** toward human." Kanae remind Shinobu. "We maybe sword practitioner, but we're not hitokiri or Shisengumi that free to kill during Bakumatsu."

"B-but… He started it first…" Shinobu uttered in shame.

"I know Shinobu. You just defend yourself, but never repeated that again." Kanae strictly said. "But you know what? Kai allow us to go back to Butterfly Estate for a while. Let use this chance to inform Oyakata-sama about this threat and starting hunt Muzan as fast as possible to face-off against this new threat." Kanae suggest.

"He… Allow that?" Shinobu didn't believe what she heard.

"Yes. Because of it, let rest for now so we can go tomorrow." Kanae replied before ready for sleep. "Goodnight Shinobu." She said before lie down and close her eyes.

Shinobu smiled at her older sister. "Goodnight Big Sister." She said before lie down and tried to sleep.

* * *

However, on the forest of Natagumo, Wakuraba is already seen appeared. The Lower Moon Three already promised Muzan that he will kill Rui and all of his families for dare to betray him.

'At last! This is what I've been waiting for! I'll get Muzan-sama acknowledgement and challenge one of the Upper Moons.' Wakuraba thought in glee knowing what price he'll get after this. 'Thanks to his blood, I already know how your abilities work Lower Moon Five. That also including your fool Oni.' He then felt something is crawling on his sleeve. Using his claws, he slash at something that's revealed to be a small spider. "Tch. Annoying creatures." He grunted as he jump from tree to tree.

* * *

However, it is revealed that the spider is one of Aiya's. She's sitting watching the full moon while keep her strings 'Someone is infiltrating this mountain!' She thought in worry. "Someone's infiltrate the mountain! Seemingly an Oni!?" She yelled.

"I'll go." Aiya gasp and behind her Rui is seen standing.

"R-Rui…" Aiya uttered. She still can't forget Rui's torture and even after his personality seemingly changed, her fear is run deep inside her head.

"Tell the others to get ready mother." Rui ordered as he using his strings to levitate himself to the air, go to the location of the intruder.

"Okay!" Aiya nod half in fear. 'I must tell the others about this!'

* * *

Wakuraba is seen jumping from tree to tree, slashing through every spiders that seemingly attacking him. "Tch. What with all of these spiders! Did Lower Moon Five making a zoo or something!" He said in frustration since all he killed till now is just a bunch of useless creatures.

However, he realized second too late as Rui is sending some of his sharp strings toward him, who managed to avoid at the cost of his left arm, who quickly regenerate.

"Tch. A good sneak attack Lower Moon Five." Wakuraba compliment as he grin finally found what he's looking for.

Rui put on his disinterest mask. "You are venturing into other Lower Moon territories. I wonder why." He said using his bored tone.

"Don't play dumb Lower Moon Five. I know you're betraying that man trust. I can't believe that you're become that foolish even though he seemingly favor you among all the other Lower Moons." Wakuraba accused him while pointing his right index finger toward him. "I'll defeat you and your pathetic family! And that man will make me his favorite!"

"You're wrong on one thing. I've never betray that man. Because…" Rui later pumping his blood to his strings then doing slashing movement toward Wakuraba, who gracefully avoid. "… I still doing evil things like he did."

"Heh. You think you stand a chance against me?" Mock Wakuraba as he dodging another strings that tried to slash him. "Too slow!"

"No. you're in precise position." Rui later bring his hand forward, creating rotating strings formation. "**Blood Demon Art: ****Kokushi Rinten****!**" He later launching rotating strings toward Wakuraba, aiming to cut him into hundreds pieces.

Wakuraba however just smirked. Suddenly elongated his claws, he doing a swing movement using both of his arms, destroying Rui's attack.

'He destroy that!' Rui thought as he sending slashing strings. However, just like his super moves, it also being destroyed by the same way.

"That's all you got Lower Moon Five? I suddenly wonder-" Suddenly, he appeared in front of Rui and punch him precisely in the gut. "-if you really that man's favorite or not!?" The punch so strong rhat it makes the Lower Moon Five being thrown several feet and his back hit a tree head-on.

"Guugh!" Rui grunted. 'I-impossible! Did I… Just being hurt! And why'd my wound didn't regenerate quickly like usual!'

"Well compare to you, my **Blood Demon Art** is not that impressive." Wakuraba then lengthen his claw once again. "My techniques allow me to elongate my fingernails then releasing strong slicing air blades. That's what I used to cut through all of your annoying threads." He explain.

'What!? With that simple **Blood Demon Art**… He become Lower Moon Three!?' Rui thought in disbelief. Usually, Twelve Demon Moons consisting of Oni that have unique **Blood Demon Arts**.

To think the one that hold simple **Blood Demon Art **can hold the position of Lower Moon is something extraordinary.

How devoted he's to Muzan?

"Now. I'll put you out of your misery." Wakuraba later bring his hand backward to perform a slashing movements. "Blood Demon Art: Kama no Kamai-" He's unable to perform his technique as a foot is planted on his face, make him launch several feet before landing safely on the ground. "Oi oi. It's not fair if there are third guests on this battle!" He yelled.

The figure that saved Rui turn out to be Shinobu Kocho, who carries her unique **Nichirin katana** but not wearing her Demon Slayer outfit.

"You…"

"I'm not saving you." Shinobu denied. "I'm here because Chisaki said you're valuable assets so he can't let you die just yet. Aiya is also the one that told me about the situation in here."

Rui silent for a moment before smirk a little. "I see." He commented as he stand up. "I'm not surprised if it like that. But, why don't your sister that going here? She can end this fight easily."

"She's tired." Shinobu simply replied before turn her attention toward Wakuraba.

"Demon Slayer on this mountain? Huh, I really can't believe Oni and Demon Slayer join forces. A strange tag-team." Wakuraba commented toward Shinobu actions of saving Rui.

"We're not friends." Shinobu said toward Wakuraba. "And I rather died than tag-team with him."

"Talk all you want. And let me guess something… Are you Tsuguko or something?" Wakuraba asked.

Shinobu just narrowed her eyes.

"So I'm right." Wakuraba said before entering fighting stance. "You think you can win? I can see little eye bags over there. Seemingly you not sleep enough. Khu khu khu…"

'He found out that quickly! That means I must kill this Oni quickly!' Shinobu thought as she entering battle stance. "No need to worry about that, since you will die tonight." She said.

"Ha ha ha! That's funny to hear! Truly." Wakuraba laughed. "Because… I not relied on just my **Blood Demon Art** like most arrogant Oni." He then suddenly disappeared.

Shinobu shocked seeing her opponent is gone instantly. 'He's move that quick!' She thought.

"I bet you're confused why'd Lower Moon like me who should be not challenging enough for Tsuguko can make your shocked because of my speed? It's not because your body condition that lack of sleep." Wakuraba said while appears between her and Rui.

"Tch." Rui later preparing his blood-echanced strings to slash him.

Shinobu quickly turn to deliver a poisonous thrust.

"Simple really." Surprisingly, using both of his leg, he kicks both Shinobu and Rui while maintaining his balance using just three fingers. "I once a member of Oniwabanshu. More exact… The one that guards the Shogun during the Bakumatsu." He revealed.

"Oniwabanshu!?" Rui said in disbelief. 'The same group that defending Tokyo or known as Edo during the Bakumatsu!'

"Bakumatsu! The time of bloody chaos that lead to Meiji Era!?" Shinobu also shock with what she heard.

"That's right. Thanks to my experience, it's enough to make me hold the position of Lower Moon Three!" He then delivering fast but precise punch to Rui's face, making him crash to a tree close to him. He then turn toward Shinobu, his claws elongated. "I'll make you pay for disturbing someone's battle!"

"Try it if you like!" '**Dance of the Dragonfly: Compound Eye Hexagon!**' Shinobu later delivering multiple thrust that seemingly targeting Wakuraba's vital.

'Aiming for my vital huh! I won't let you!' Using his experience in facing thrusting attack during the Bakumatsu, Wakuraba make a bold decision. He stop Shinobu **Nichirin katana** using his hand that's revealed being covered with iron gloves to stop each stab that precisely targeting all of his vital. However, he misses one thrust that managed to pierce his right shoulder. 'Tch, it's so many that I miss one strike to block! But wait a second! This is…'

'I won!' Shinobu thought triumph. However, her triumphs soon turn into horror when Wakuraba suddenly grab the **Nichirin katana** using his other hand, snapping it in half. "B-but…"

"I know that you're aiming to inject **Wisteria Flower Poison** into me but… That **Nichirin katana** you're using is run out of it. I can't believe that luck fall to an Oni like me." He then kick Shinobu, making her stumble backward. Using the momentum, Wakuraba jump backward while preparing one of his **Blood Demon Art**. '**Blood Demon Art: ****Kama no Kamaitachi****!**' Wakuraba later doing slashing movement to the empty air, delivering a sharp, razor-sharp air blade that slice Shinobu's torso, injuring her left lung. "A…Agh…" Shinobu later drop down on her back to the ground.

Rui, who seeing the attack later act quickly. "Tch. Just die!" He then creating a web formation on both of his palm. "**Blood Demon Art: ****Ayame-kago****!**" A ball of sharp strings later form around Wakuraba. "Being sliced to little pieces!" Rui later shrinking the ball using his left hand, while his other hand sending his strings toward fallen Demon Slayer to stitching her wounds.

"Weak! **Blood Demon Art: ****Tsujumikaze**!" Wakuraba later doing rotating slashing movement, creating whirlwind-shaped air blades that cut through all the strings. "It's useless brat!" He yelled as he launch toward Rui.

"I won't lose that easily!" Rui later brandishing spider web-shaped strings to attack.

"You can't ever beat me!" Wakuraba said as he using his air blades to cut through the strings. Rui later preparing a stance, releasing another collection of strings to slash his adversaries.

Meanwhile, Shinobu found herself hard to breathe due to her lung injuries and she's still lying on the ground. She really hated herself. Why she must be born with this weak little body? Why can't she become like her sister who can cut Oni's head?

Shinobu then tried to get up but immeadiately fall if she not support her body with her right hand. Her left hand later form a fist and she punch the ground repeatedly in frustration while tear is seen streaming down from her eyes. 'Useless! Useless! I'm such a useless! Not worthy! Weak! Why Buddha!? Why'd you so mean to me!? Thanks to this body… I… I can never protect Big Sister…' She thought in frustration as she continues to cry.

"Don't ever cry Shinobu."

Shinobu suddenly widen her eyes, remembering some memories during her training with Kanae.

**(Flashback – One year ago)**

Thirteen years old Shinobu is seen sparring with Kanae using bokken in the Butterfly Estate. However, the much stronger Kanae is easily dominating the spar, before it ended with Kanae won the battle by her bokken touching her sister neck.

"I win this round again." Kanae declared.

"As expected of Big Sister." Shinobu commented while being support to stand by Kanae.

"For now, just rest before I go to the next mission tomorrow." Kanae said as she walks inside the estate.

Shinobu however not finished yet. "Big Sister." She called.

Kanae later turn around. "What is it Shinobu?" She asked curiously after seeing her sister's expression that seemingly not fond of something.

"Big sister… Do you think that I… With this weak and small body… Can become a strong Demon Slayer just like you and Mr. Himejima?" She bluntly asked.

Kanae sighed. She always know that Shinobu is jealous for her lack of strength. "Shinobu, didn't I tell you-"

"I DON'T ASK FOR YOU TO PITY ME!?" Shinobu suddenly yelled. "Let me tell you Big Sister…. I'm frustrated! You managed to cut off Oni's head after few years of training under Mr. Himejima! While look at me! All I can do is delivering poisonous thrust which of course useful but let's not forget that time when a Oni can survive my poisonous thrust and will kill me if not because of Big Sister!" She then started to sob. "If I can't become stronger… How can I protect you, Big Sister…" She uttered as she now crying.

"Shinobu…" Kanae later walk toward her only sister, and hug her tightly. "Please Shinobu. Don't ever cry." She said while she's starting to cry as well. "If you sad… I'm sad as well…"

"I… Just don't want to lose another one of my family again…." Shinobu said as she cried harder.

Kanae can't say anything but encouragement toward Shinobu. "But at least you know what did you do if you face an Oni do you?" She asked.

Shinobu nod, despite crying. "Once I decided to defeat an Oni, defeat it. Once I decided to win against an Oni…

**(Flashback End)**

'I MUST WIN!' "U-u-u-ugh…" Shinobu later struggled to stand up. She then look toward Rui, who surprisingly still manage to hold his own against Wakuraba.

Wakuraba seeing that Shinobu is managed to stand up while he's still clashing against Rui. 'Impossible! She shouldn't be able to stand! My attack is slash her left lung! She must be had difficulty breathing now.'

"I have to admit for someone who have the same weak body as me when I was human… You're pretty tough." Rui compliment while attack Wakuraba, who drop his guard down with a fist that make him fall to the ground.

"Hah… Hah… Hah…" Shinobu unable to talk. Her damaged left lung prevented her from doing so. However, she look intently toward Wakuraba. 'Even though my **Nichirin katana** is snapped… I can at least cut his neck off. Using the momentum of my strongest move.' Shinobu later took a stance, before suddenly disappeared. However, speck of dust shown that she moves so fast in zigzag.

'This is… Two steps below **Shukuchi**!' Wakuraba thought in disbelief. He then manages to kick Rui out of the way and focusing his intention toward Shinobu. However, her zigzagging movement make the Lower Moon Three is confused where to aim his attack. When suddenly, she's appears few meters in front of him. "What!?" He immediately is using both of his arm to cover his neck from the attack.

'**Dance of the Centipede: Hundred-Legged Zigzag!**' Shinobu later using the momentum of her **Shukuchi**-like movement, delivering powerful thrust toward Wakuraba's neck after pierce through his arm. However, the thrust only stop there due to the snapped **Nichirin katana** and Shinobu weakened body.

'What the!?' Wakuraba only widen his eyes as the thrust is aiming to cut off his neck from the rest of his body. This make him enraged. "Enough of this!" He later delivering an upward kick toward Shinobu chin, hitting it cleanly and make her fall to the ground. Not forgetting Rui, he later decided to finish him off. "Now then. Seemingly you're lost your regeneration power huh? That's fine. That man himself will finish you off. I'll finish you with my strongest attack. **Blood Demon Art**." Wakuraba's claws later elongated. "**Kamaitachi Midareuchi**!" He later swing his arm in rapid succession, creating a barrage of air blades that will cut Rui to pieces if a wall of ground not protecting him.

Kai is seen walking toward Rui, who still can't stand because of his injuries.

"Kai-san…" Rui not believing that he will come personally.

"I come here personally, because you and Shinobu took to long. And Kanae need a rest. It will be more faster if you tag-team against him." Kai inform before turning his attention toward Wakuraba. "Anyway, he's pretty strong isn't he?"

"So you must be the man that beat Lower Moon Five. The one that he's talking about." Wakuraba guessed. "How lucky I am. That means I get two dinners."

"You're wrong on one thing." Kai later using his Quirk on the ground, sending drill-shaped ground that spinning toward Wakuraba, who manage to avoid. "I'm just here to get back my two comrades. That's all." He later make the ground around Shinobu rise, making her thrown to the air before he catches her using constricting whip that make using forest floor. He then hold her small body on his arm.

"So you want to steal my prey. You worry so much about them do you?" Wakuraba later elongating his claw once again. "Then all you three can meet again in hell. **Blood Demon Art: ****Kamaitachi Midareuchi**!" He later using the same technique that he used against Rui toward Kai, sending a barrage of air blades.

"Annoying." Kai later makes his hand touches the ground once again, sending several stone spears toward Wakuraba, the spears is being cut to shreds. Wakuraba later using the chance to move toward Kai. He tried to slash him in close-range, but Kai easily duck the attack and tried to **Overhaul** the Lower Moon Three body.

'This aura!' Wakuraba thought on heavy caution as he quickly leaps backward, avoiding Kai's deadly hand just in time. "I'm surprised really. I've never thought human with body speed such as yours exist. I think only during Bakumatsu that someone manages to reach that kind of inhuman speed without using **Breath Styles**." He compliments.

"I already use to dodge thing as fast as bullet shoot from the fastest gun. It's not something to praise." Kai said. "Because anyway, seemingly there's someone who watching us the entire time."

True to what Kai predicted, an old man on his late 50s is seen emerge from the dark part of the forest. "At last I found you, Wakuraba." The old man have short white hair with a little black streaks on it that being cut in neatly in back but with a distinctive fringe of permed bangs falling in front of his face and parted in the center. He most distinctive feature is his eyes, which are a piercing, ice-cold blue. He sports decidedly Western dress in the form of a deep blue, collarless short-sleeved dress shirt with a goldenrod trim, matching deep blue slacks and shiny black dress shoes. More distinctive still is his coat - a long, sweeping trench coat of light tan with a ribbed goldenrod interior trim. He also wears deep blue, wide-mouthed fingerless gloves. He also carrying a long nodachi on his hand. "Seemingly you become an Oni at your own free will. A disappointment for the Oniwabanshu."

Wakuraba later turn toward the newcomer, but widen his eyes after knowing who he is. "I-impossible… You're still alive… Aoshi-sama?" He asked in disbelief while revealing the name of the mysterious man at the same time.

"Thanks to you, the one that already dead can't rest in peace. For that-" He later unsheathe the nodachi, which later revealed to be a pair of kodachi. "-As the former leader of the Oniwabanshu, is my job to clean my own evil underlings."

Shinobu, who listening despite her injuries, is shocked. 'This man… He's the leader of the Oniwabanshu…'

'This man... I see. He's that famous assassin during the early part of the Meiji Era. The prodigy leader of the Oniwabanshu... Aoshi Shinomori!' Rui thought, finally remembering the old man that now facing Wakuraba.

"Humph! That's funny! You who lose against Battousai and now an old man… What can you do with that weak old body!" Wakuraba argued while launch toward him.

However, Aoshi suddenly take a stance. He suddenly disappeared before suddenly appear behind Wakuraba.

Wakuraba look behind him in shock. 'His speed isn't even diminishing! It's still likes him as the young boss!?'

Suddenly, Aoshi passing Wakuraba, and the Lower Moon Three is being cut into six pieces. "**Oniwabanshu kodachi nito-ryuu: Kaiten Kenbu Rokuren.**"

'I-I being decapitate!' Wakuraba thought in disbelief. 'By him! Even though he's an old man! And he's using **Nichirin katana**! Impossible! Where'd he got those in the first place!?' His body and his head later started to turn into ash. "H-how could this be!? You're just weak old man!" He yelled as his body is completely turn into ash. Wakuraba, the former Oniwabanshu and the Lower Moon Three of the Twelve Demon Moons is now dead.

"There's nothing wrong. You still weak during your time in Oniwabanshu." Aoshi replied befor look at Kai. "I've never seen you face before. But sorry for interrupting, since he's my responsibility to handle."

"That's fine. Because I actually had no concern of him in the first place." Kai replied. 'This man is dangerous! Maybe I can still beat him but… I don't want to look for much trouble right now.' He thought.

'I not cornered him. All I did was giving Rui burden by my injuries.' Shinobu thought in frustration.

"I see." Aoshi simply said before turn his back and walking down the Natagumo Mountain.

Rui later stand up after feeling his injuries being healed. Although his regeneration cells is being destroyed by **Overhaul**, his body still able to heal much faster than normal human. "You let him get away. Why?" He asked.

"He had no intention to disturb us and he also only hunt down that Oni." Kai replied. "I must take care of you and Shinobu injuries. Thanks to you stitching her wounds, Shinobu still manage to escape death."

"I'm glad then, since she's supporting me." Rui replied. 'But… I never thought that there are members of former Oniwabanshu that still alive in this Taisho Era and still not losing his teeth... Is terrifying!'

"Rui." Kai called while he already walking toward the temple. "You want to be burn by sun there?"

"I'll catch on." Rui replied as he turn and following Kai toward the temple.

* * *

Shinobu is seen standing on a deep forest. She then look around, confused.

'Where is this!' She thought in confusion.

"Ah so you're the one…" Said someone who appears by mysteriously covered in shadow. "… That this weak woman told about." He then throw something toward Shinobu, who later look down and horrified.

It was Kanae's decapitated head. Her eyes closed.

Shinobu suddenly had the urge to puke, but fight and look toward the shadowy being in hatred. Her mind is fill with rage. "I'LL KILL YOU!" She yelled before dash forward.

"Kill me?" The shadowy figure lightly said while brandishing pair of sharp iron fans. "That's funny!" He later managed to slice Shinobu torso before she could even react.

'Again…' Shinobu thought before falls to the ground.

"You're weak." The shadowy figure said. "That's maybe because your small body am I right? With that… You can't protect anything."

Shinobu grit her teeth in anger.

"Now then, I recently found a cute little girl that tried to attack me." The shadowy figure said before showing her headless body of Kanao Tsuyuri. "Is she yours perhaps?"

'No… No... No... No... NOOOOOOO!'

* * *

Shinobu later wake up with cold sweat all over her face and immediately sit up while panting. She then see that she's inside the temple. The sunlight shown it is already morning. 'It just a dream! It just a dream! Not real!' She thought in relief while touching her chest. 'I see. I am healed by Chisaki… Again.' She thought while a lone tear is fall from her eyes before she look down and grip the blanket that cover her body in frustration. "Why… I'm so weak…"

"Shinobu…" Shinobu then seeing that Kanae is sleeping while her body is lean back to the wooden wall of the temple.

Kanae then wake up from her sleep, rubbing her eyes before seeing that Shinobu is awake. "Shinobu!" Kanae quickly rush and hug her. "I'm so glad! Sorry for being such a bad Older Sister! I heard all from Rui. He said you fought bravely!"

"Big Sister… I…" Shinobu unable to said what's inside her mind. 'Rui… Why'd you lie to Big Sister? Why don't you tell the truth… That I being nothing but Lower Moon Three punching bag…' She thought while she return the hug of Kanae.

"Anyway, you should wash yourself first. Sofia said to me there's small waterfall close to the temple that can be use." Kanae inform.

"…Okay…" Shinobu replied.

* * *

After Shinobu is finishing wash herself, the Kocho sisters later bid their farewell to Kai, who currently discuss with Sofia about Kai's plan to build a larger underground base.

"I see. Then, I give you two weeks. That's more than enough right?" Kai demanded.

"It's more than enough. Did I shall tell about you to Oyakata-sama?" Kanae asked.

"No. Remember that my warning that time still exist." Kai threaten. "I expect both of you to return in two weeks. Is that clear?"

Kanae nod.

"Wait a minute." Sofia later pick her cross necklace from her pocket and give it to Kanae. "Take this. May God always protect you." She prayed.

Kanae smiled and received it. "Thanks Sofia." She later hug the former Eldest Sister Spider Demon.

* * *

After bid farewell, both Kanae and Shinobu begin their journey back to the Butterfly Estate. Currently, they already down from Natagumo Mountain and currently on the plains.

"It's must be fun to be able to return to Kanao and the others for a while. Right Shinobu?" Kanae said in happiness before looking at her younger sister. But, she later notices that Shinobu seemingly sad. "Shinobu?"

Shinobu is realized that her sister called her. She then look at her with a fake smile. "Yes Big Sister. I think it will be fun to being released from Chisaki even just for two weeks! At last we can seeing Kanao and the others."

"You're seem sad Shinobu." Kanae immediately pointed.

Shinobu widen her eyes. She forgot how sharp her sister in pointing her face. "No Big Sister. I… Just sad because I as a Demon Slayer, support an Oni in battle." She lied.

"Please put that feelings away Shinobu. If I in the same position as Rui, I think I'll accept Muzan proposal due to my body condition." Kanae said. She then pinch Shinobu cheek, forcing her to smile. "Come now, you don't want Kanao and the others see you sad do you?"

Shinobu then forced to free herself from her sister grip. "Of course I don't want to!"

Kanae later giggling. "That's Shinobu that I always know. Brash and straightforward."

Shinobu later giggling as well. 'Big Sister… I already make my decision…'

* * *

At night, they finally reach a village and decided to stay for one night before continuing their journey.

However, Shinobu is secretly putting a sleeping powder to Kanae's drink, making her heavily asleep.

Shinobu is seen awake while fixing her equipment. She also secretly switch her **Nichirin katana** with Kanae's, with only the sheath that don't change. "Sorry Big Sister. But… At least for two years, I'll throw away my life as a Demon Slayer… and Yakuza." Shinobu then gently pat her sister cheek. "I'm sorry for stealing your **Nichirin katana** but… I must become stronger to protect you and anyone that's important to me. Farewell Kanae-neechan." She bid her older sister before leaving the lodge that they stay for a night.

**Notes:**

**And the chapter finally finished! The next chapter will more told about Kanae and Shinobu and we will become absent from Kai for a while. Since both of them are the important characters on this story.**

**Now for the case of Wakuraba being former Oniwabanshu, I already tell that this story is Triple Crossover of Demon Slayer, My Hero, and Rurouni Kenshin. Because of that, I think dear readers should not be surprised if there are elements or characters from Rurouni Kenshin that appears, like the example of Aoshi Shinomori in this chapter. I also plan to tell how Muzan movements are during the time of Rurouni Kenshin storyline. Although if I put Rurouni Kenshin characters, I'm pretty sure that all of them during this Taisho Era is an old man or women. By the way, I put this story in 1912, the first year of Taisho. Since I already that this story takes two years before Kamado family demise, that event will happen in 1914.**

**By the way, I got inspiration for Wakuraba Blood Demon Art from One Piece Kama Kama no Mi.**

**See you in the next update.**


	7. Chapter 7:Encountering Wolf of Mibu

**/N: Boku no Hero Academia is written and illustrated by Kouhei Horikoshi. Kimetsu no Yaiba is written and illustrated by Koyoharu Goutoge. Rurouni Kenshin is written and illustrated by Nobuhiro Watsuki. I don't own the three of them.**

* * *

**How to read the story**

In the… – Normal

"You're…" – Conversation

'Why…' – Thought and telepathic communication

Kagune – Foreign words

"**Fired…"** – Deep Voice

**Tetsusaiga** – Technique, Quirk and special weapons

* * *

**Chapter 7**

**Encountering Wolf of Mibu**

Time finally switch to dawn, as the sun starting to rise from the horizon. On the lodge where Kocho Sisters are resting for one night before continuing their journey back to the Butterfly Estate, Morning light lighten the room.

Kanae Kocho finally awake from her sleep. She's unaware that last night Shinobu is pouring sleeping powder into her drink, making her unable to hear anything and put her in a very deep sleep. Stretching her arms, she then yawn while look at her surroundings.

'It's morning already.' She noted before seeing her surrounding, only to found that Shinobu is nowhere to be seen. "I wonder where Shinobu is gone…" She then giggling. "…Maybe she buy snack for morning. She's surely not change at all. Now then, time to check my **Nichirin katana **then." Kanae then stand up and pick her **Nichirin katana**. She then unsheathe it from its scabbards, only to find out that it's not her, but Shinobu broken **Nichirin katana** from result of her fighting against Wakuraba on Natagumo Mountain.

"T-this is…" Kanae later seen there's a paper that wrapped on her scabbard. "Is… This… an letter?" She then pick it up and open the letter, only for the Flower Pillar to widen her eyes, not expecting the content.

* * *

Dear Sister,

I'm sorry for not telling you and taking your **Nichirin katana**, but I think you'll soon discovering this letter after you're wake up from the sleeping powder that I gave you last night.

The truth is… I want to throw all my life for a while to travel around Japan so I can become stronger. I just go to the point Big Sister, I hate myself. I hate how my body is so weak in comparison to the others. Even others in Demon Slayer Corps who're younger than me can cut through Oni's neck. Even Kanao can do that. But… I'm so frustrated that all I can do is useless thrusting attack that must relied on poison. And after meeting Chisaki and join Shie Hassaikai, only make me more frustrated. I lost to him and his strange abilities, and I can't hold to curse myself when I must relied on the others to support me in a battle during Natagumo Mountain Raid and against Lower Moon Three. If it keep continuing like this, if I not train in my own ways, I can become crazy.

No need to search for me Big Sister. I maybe will go at least two to three years, so I can become stronger to protect you, the one that I treasured so much and my home: Demon Slayer Corps, Butterfly Estate, and although it's hard to admit it… Shie Hassaikai. Give my regards to Oyakata-sama and Chisaki. I hope your safe on your journey back.

From your younger sister,

Shinobu Kocho.

* * *

Kanae unable to hold her tears, making her personality flip from happiness to sadness. She later put her left palm on her mouth while crying. "Shinobu… Why…" She uttered. 'I… Don't want you to curse yourself Shinobu. Didn't I say before… You can defend yourself is enough for me…' She thought as she continuing to cry for the next 60 minutes. "If you gone like this… What shall I tell the others…"

* * *

On Natagumo Mountain, Kai along with Sofia is on the underground base that already being cleaned and later being fixed into a fit shape using Kai's **Overhaul**. Since Kanae and Shinobu gone for a while, Kai asking for Sofia's help to help him in his experiments on Oni's cells, but he must teach the female Spider Oni about biology for a moment, which he slightly didn't like. He already did this since yesterday when Kanae and Shinobu are leaving without any rest.

With some existing bottle that he make using his Quirk, Kai's separating the blood that he got from Sofia and Rui to be examined. He then widen his eyes after realizing something. "So that's it. The secret of Oni cells." He said.

"Did it already finish, Chisaki-san?" Sofia asked while tidy up the bottle that being used for the experiments.

"I finally found it. The type of cells that must be removed for all of you to be able to walk in the sun again." Kai replied. "Gather all of Spider Family. This big invention must be inform immediately." He ordered.

Sofia however frown. "That's not a good idea Chisaki-san. Since our blood still had that man cells on it, it mean he can monitor all of our movement easily and gathering information secretly. I think you shall not tell any Spider Family for now."

"That I already know. Although a coward he surely very careful with his pieces." Kai admit. "The thing that I must do is to test it immediately, faster than Muzan can gather the information."

* * *

Back to Shinobu, the younger of the Kocho sisters is seen already travelling miles away from the village lodge. She currently doesn't know where to go. She just aimlessly wander to at least avoiding contact with her Demon Slayer Corps, her sister, or Chisaki and Spider Family. She's mad at her own weakness. Before she has any face to face any of them, she must become stronger.

'But… I actually don't know how.' Shinobu thought to herself as she continuing to walk on the road without clear destination to go.

After some time wandering, she's tired and decided to sit on the ground slope that facing a rich paddy field. While watching the beautiful landscape, she spent her time lamenting and cursing herself for her own weakness.

"I wonder… Where I will go? With the money that I have now, it's impossible to paid a lodge for a night. Maybe I'll search for a villagers house that saved by us then. But… If I doing that, Demon Slayer Corps will know where my position." She uttered. "If I not wrong, this place is close to Kyoto. I maybe will go there." She then stand up, preparing to walk toward her decided destination.

However, she's not realized she being watch by someone from the distance who riding a horse carriage. It was an old man on his late 60s that seemingly had healthy body despite of his age. His face already wrinkled but he had a very sharp yellow-eyes and white hair with spider-like strands on his front and a long ponytail. He wearing a formal blue uniform and look at Shinobu, who some eighty meters away with a neutral look.

"Maybe she's forgotten or something but there is no police that wearing those kind of uniform. And the fact she's carrying a katana despite being wrap in fabric is violation to today law since I find it hard to believe that young girl like that is a part of Yakuza or the new Juppongatana that become a threat to this Taisho Era." He commented before looking toward the other in the carriage. He was a man probably around his early 50s. His appearance including a very long white hair with some blonde color still exist that raise upward much like a broom and yellow eyes with one of them closed. He is wearing surprisingly a standard kimono with flame pattern haori on his back. "So this is the Demon Slayer Corps? What Hijikata Toshizo said during Bakumatsu is true after all… There are a groups of swordsman that specialized in killing being known as Oni."

"That's true." The man said. "I actually don't believe at first. But since I encounter Aoshi Shinomori on my way here and also thanks to the information that long time ago said by Shishio-sama prove it. Demon Slayer Corps… An organization obscured from government view with the aim of eradicating Oni is exists… As well as Oni itself." He said. "Then… What you'll do?"

"Capturing a young girl is actually not my liking. I don't know how their standard actually by inviting such young age, even a women nonetheless. I'm pretty sure if that Raccoon girl is here, she must be not agreeing non-stop with this. I don't know for Battousai though…" He uttered. "Well maybe he won't complain, since he's now become weaker than he used to be."

"So you will capture her then?" The other man asked. "If you want, I can do it. Since you're old man now."

"There's no need for. Judging from the direction, she's walking to Kyoto. Eiji is stationed in there for a while. I already sent telegram to him ever since I following that girl. If can-" He later revealed a guntou on the carriage. "-It's been a while… Since the Wolf of Mibu can show its fangs to those who don't listen to the law."

* * *

On Kanae side, she already paid the lodge, before walking across the village on her way back to the Butterfly Estate. She still can't hold her sadness because of Shinobu selfish decision. She never expected that the fact she loathed all the other Demon Slayer so much that make her developing inferiority issue. How great she become her older sister, never realizing something such simple.

'Why'd I never realized it ever since she can't cut Oni's head? Did she loath the others… Including me so much? If at least I decided to teach her from the start to break that limit of her… Then all of this never happened…' She thought while her eyes are still watery after crying on the lodge. "I… Such a fool of a sister… I never know... She's suffering so much..." She uttered before seeing someone that she didn't expect.

"Kanae!" The one that is revealed to be Sanemi is racing toward her when he seeing the Flower Pillar.

"Sanemi…" She didn't expect that her fellow Pillars is searching for her.

Sanemi later stop in front of her and grip her shoulders. "You fool! Where'd you and Shinobu go all this time!? Oyakata-sama and the others in the Butterfly Estate is worried about you!?" He yelled when he notices something. "By the way… Where's Shinobu?"

Kanae can't hold it anymore. She then look down while sobbing.

Sanemi who seeing this is immediately react. "Oi Kanae! What happen to Shinobu!? Did she killed!? Who's Oni that responsible huh!? I'll skewer his head and make it being my personal trophy!?"

'It's not like that!' Kanae thought while continuing to cry. 'I… Can't tell… Why…' "She… she…"

"If you can't talk right now, let's go back to the headquarters." Sanemi low his tone. "I'm sure the others can cheer you up."

Kanae later look at Sanemi and slightly smile before wiping her tears. "Thank you very much Sanemi. I… Really need some time to rest right now…"

Sanemi merely nod. The two of them later walk from the city toward the Butterfly Estate.

* * *

Back to Shinobu, she finally arrived in Kyoto, more precisely at the capital city. The Westernization that happens since Meiji Era already had shown how much Japan changed. The building in the capital city start to showed its western culture, plus the appearance of primitive car and electricity on the place. The town is the staying place of the rich and government people.

Which is why the town or public transportation like train is a dangerous place enough to make every Demon Slayer rarely go to there. Since the guntou is now forbidden except for the police and military thanks to the westernization, each Demon Slayer, even Pillars rarely dared to entering a city. Even during the early part of Meiji , Shinobu once heard a story about one Pillar that being captured and imprisoned for dared walk freely in Kyoto.

In truth, Shinobu is wary being in here. Although her **Nichirin katana** maybe wrapped by a simple fabric so it looks like that she's carrying a staff, her outfits that almost resembling police unit gain attention of many people around. She forgot to change to her disguising kimono, which available in the backpack she carry. Plus, she's a girl. There's rarely a girl is working for police profession on the front-line during this time.

"Hey, look at that girl."

"Why's the girl as young as her work for the police?"

"Is the government starting to show its rotten side?"

Shinobu didn't paid mind to them as she continue to walk. It's very common to see something like this. Usually the police won't paid attention as long as she not causing any suspicion.

But this time one police seemingly become suspicious of her. Not far behind, a police is seen following the younger Kocho sisters from a car. He wears a Japanese police uniform plus a hat and a guntou on his waist. Below the hat, he had brown hair and brown eyes despite having some wrinkles due to his age that seemingly on his 40s. Judging from clothes, he seemingly a high-rank officer "It all makes sense now after Fujita-sama contact me from the telegram. The girl wearing a strange clothes and carrying a katana that being obscured by fabric. But… I seemingly know her…"

"Eiji-sama." A low-rank officer who sat beside him called. "What shall we do?" He asked.

"Keep following her." The police officer now known as Eiji said. "If Fujita-sama really that wary of her ever since he saw her, we must at least capture her for question." He then light up a cigarette. "So this is that so-called Demon Slayer Corps. We, the police government will make sure to make your existence known."

* * *

On Shinobu side, not realizing she's being followed, she then entering a changing room on one of the buildings. Not long after, she come out, having changing her Demon Slayer uniform and haori into a pink kimono like Kanao use to wear, although her **Nichirin katana** is still must carried by her like a staff all the time. She then continue her aimless wandering, although she seemingly realized something is wrong. She then glance backward, seeing that a car is seemingly following her. 'I wonder… Why's that car seemingly following my movement?' She thought.

"There she is!"

"The Demon Slayer Corps!"

Shinobu widen her eyes in shock when seeing groups of police are blocking her way forward with their plastic guntou. 'A police!? Since when-' She then see again the car that's exist behind her. 'That car must be a police officer of this city! Why'd I not realize it!'

"She seems being surrounded by our men. We can capture her." The low-rank officer that accompany Eiji said.

"Not now. Believe me we must chase her." Eiji not agree. "For someone that spent their time to battle… I know for sure… She isn't on human level."

True to what Eiji predicted, Shinobu suddenly disappeared, only to find standing on an electric pole. She then jumps down and run away from the scene 'No way I'll risk facing them. There's many innocent people in here! I must at least reach the tip of this district to escape their view!'

"Impossible! She disappeared and then appears behind us!" One of the police said.

"Chase her!" One of the police ordered his comrades. Soon, they began to pursue Shinobu.

Eiji smiled seeing that Shinobu is running away. "After her." He ordered the police that drive his car.

"Will do." The car later goes at the top speed of the current car can do on this Taisho Era, chasing after Shinobu.

* * *

Meanwhile, Shinobu manage to outrun the polices that chase after her when she found a corridor and quickly turn and hide behind a high trashcan. When all of them pass, she sigh in relief. "At least I manage to escape them. However, why'd police act hostile like that? If I remember… Big Sister once mention to me that the police usually only ask her few questions before leaving her…" She uttered. "That polices surely a sharp one... Different than the one we usually met."

"Oh. That means I must punish the polices you're talking about for easily let go someone who's breaking the law."

Shinobu now more shocked hearing the voice. She then turn her head toward the passage and seeing the old man from the carriage is standing with a guntou on his waist.

"I bet on just forty percent that you'll go to this narrow passage. Although I actually never expected that you're managed to escape the polices that easily without killing them. And you fall to the bait." The man said to himself as he unsheathed his guntou. "Now then, if you just kind enough to let me capture you without a fight. Because you see… Different from the police of this time, I won't hesitate using this to kill you."

Shinobu become wary of this old man. She doesn't see him as a normal old man at all. His body for an old man is rather muscular like that of Urokodaki Sakonji. And the guntou that he carried somehow giving the same impression as **Nichirin katana**.

"Don't speak huh?" The man suddenly going a weird stance of thrust. Dropping into a partial crouch, both knees bent, left arm drawn back and right arm extended forward; he grasps the hilt of his guntou with his left hand and rests the tips of the fingers of his right hand on the blade near the guntou's tip. "It's been a while, since I can wield a sword seriously. I hope your Demon Slayer **Nichirin katana** over there not just for show." He said with sarcastic tone.

'What shall I do? There's no way for me to run away. If I get out from this passage, I'm pretty sure the police will spotted me. This old geezer… He can predict it that far? But did he a police… I'm pretty sure he already on his late 60s. Could he be a senior police?' Shinobu decided there's no other way but to at least incapacitate this old man to get away. Releasing the fabric, she revealing her older sister sheathed **Nichirin katana**. However, keeping Demon Slayer's oath that never pointing their weapon toward human, she warned him. "Since I can't get away I'll tell you something old man. I don't use this katana to hurt innocent human, only Oni. So please, I can explain the reason of why'd I bring this katana to you."

The man however chuckles, like he was mocking the younger of the Kocho sisters "If that so, then all of your life of holding that thing is a joke. When person hold katana, no matter how their goal is, katana is a weapon for murder others no matter." He said in disgust. "And I can see clearly from your face. A face of someone that's run away because cursing her own weakness."

Shinobu narrowed her eyes hearing his mocking now reach personal level. Her right hand unconsciously touch the hilt of her sister **Nichirin katana**, tried to pull it out. "Silence…" She uttered. She's angry at this old man, but tried her best not to let emotion controlling her decision.

"So you already arrived first Tou-san." Said a voice behind Shinobu that's revealed to be Eiji. "Forgive me, but she's more agile than I thought. Let me capture her. Your body is not a body to fight anymore."

"Eiji…" The man said, recognizing Eiji. He then surprisingly dropping his strange stance. "If that's what you want. After all, I had no right anymore to capture her. For my body, you shall not worried about it."

'Wait a minute!' Shinobu widen her eyes hearing the name. She quickly turn around and seeing that the police officer is someone that he recognize very well. "Eiji-jiisan…." She said in disbelief. Here in front of her, stood Mishima Eiji, the former neighbor of Kocho's family and Arata Eiji's Father.

Eiji slightly widen his eyes. "Did I know you? You must already know that carrying a katana except for the polices are forbidden since Meiji Restoration. I'll take you to the office now." He stated.

"Eiji-jiisan it's me Shinobu!" Shinobu said to him. "I'm the younger daughter of the Kocho family! Do you remember me?"

"Shinobu?" Eiji said in confusion. Tried to remember something.

"Did you know this girl Eiji? Judging from her tone, I think she's not lying." The old man asked.

Eiji then slightly widen his eyes. "Shinobu… Now I remember. You're Doctor Kocho youngest daughter…"

Shinobu unexpectedly run toward him and hug the police officer. "I miss you…. Where'd you go all this time?"

Eiji however releasing the hug immediately and look at her seriously. "Shinobu Kocho. You're under arrest for violating the law of bringing katana in the public. I expect some explanation at the office." He stated. However, he leaning close to her ear and whispering something. "I'm glad that you still okay."

Shinobu not expecting his reply. He hope that at least Eiji will let her go while question her in place. But… Under arrest? However, she feels at ease a little because the police officer still remember her.

"You can't underestimate Eiji Butterfly girl." The old man suddenly said while still standing behind her. He put one of his hand on his hips. "I already teach him very well to make him prioritize mission first. So, no matter if you his acquaintance or someone related by blood, if you're violating the law, you'll go under arrest."

Shinobu look at Saito with narrowed eyes.

"You shall be glad that you're caught by me Shinobu. Because if Tou-san is the one that catches you, I'm pretty sure he'll use his guntou to incapacitate you." Eiji said to her.

"This old man is your father?" Shinobu asked in surprise.

"Fujita Goro at your service." Saito using the name he use during the Meiji Era to introduce himself. He bowed a little.

'Fujita… Goro? If I not wrong… Isn't he the famous police inspector during the early parts of the Meiji…' Shinobu remembered that name from the history books that Kanae usually lend her. "You're… That Fujita Goro?"

The old man, now known as Fujita just nod.

"Now Shinobu." Eiji later pick up an iron handcuffs from his pocket. "I suggest it's time to go to the office for investigation."

* * *

Although Eiji said it's for investigation, he brought Shinobu to the place she didn't expect.

"I'll investigate you personally in my home." Eiji said to Shinobu, who's sitting on his car while had her hands being cuffed. Fujita is also seen sitting beside her.

"Hmph. It's the same as you spare him Eiji." Fujita scoffed. "I'd expect you'll investigate her on the prison."

"No need to worry Tou-san. I'm pretty sure she's innocent and will cooperate with us." Eiji replied with a smile.

"In other words, you had your personal feelings got in the way again?" Saito asked. "Did you forgot what I told you?"

"I've never forgot it Tou-san. I can promise you the investigation will be fair and square even it's Shinobu that will I investigate." Eiji assured his adoptive father.

Shinobu feel not right being silent all the times, so she decided to speak. "Um… Eiji-jiisan. How are you right now?" She asked.

"I'm fine." He replied. "The last time I saw you, it's when you're still a little girl along with Kanae. I believe it's already seven years have passed. But, I still can't believe that Doctor Kocho is dead. I'm sorry because of it."

"But I've never expected you're a police officer." Shinobu said.

Eiji later smiled while closing his eyes. "I was stay on a secret mission to watch over a certain criminal that hide in your village. Then I find out that he's targeting the richest man in that village, your parents. Luckily, I and this guntou manage to bring it to justice."

Shinobu gasp. Does that mean he kill the criminal?

"So you kill him huh? Seemingly Aku. Soku. Zan principal really suits you." Saito compliment with a smile.

"Don't talk like that Tou-san. We had a girl inside my car." Eiji said a little embarrassed. "Well. We've arrived."

On the outside, lied a large mansion. This is Mishima Eiji house.

* * *

On Kanae side, she finally reach the Butterfly Estate at night after a long walk with Sanemi. The older Kocho still had a sad look on her face because of Shinobu's sudden departure. This is not missed by Sanemi, who had a concerned look on his face.

"Oi Kanae. I know you're sad, but you can't show that face to the others." Sanemi remind her.

"I understand." Kanae nod while tried her best to smile.

Sanemi sigh, before patting her right shoulder. "I'll stay for one night to accompany you. And if you can… Show the usual smile of Flower Pillar while I stay." He said before walking toward the Butterfly Estate, leaving Kanae to look at his back with a smile. "Sanemi… You truly are…"

* * *

Inside the Butterfly Estate, Aoi seen cleaning the floor when someone is knocking the door. "Wait for a moment." She said before stand up and walks toward the door to open it. When its open, she open her mouth in disbelieved.

"As always you're so diligent to cleaning the estate, Aoi." Kanae greet with a smile.

Aoi immediately hug the Flower Pillar while had tears on her eyes. "Kanae-sama!" She cried.

"Kanae-sama!" Kiyo, Naho, and Sumi also appears from one of the room inside the estate. "You're back!"

"Hello everyone." Kanae greet them before looking at the last person that not greet her.

Kanao is seen just closed her eyes and smiled. Even till now, she still can't show her emotions. But Kanae known inside her heart she's relief that her older sister is back.

Kanae later releasing Aoi's hug. "All of you. Sanemi will stay at here for a night. Can all of you please prepared a room for him?" She asked kindly.

"Of course!" Kiyo, Naho, and Sumi immediately walk to the closest room to prepare it for Sanemi. Kanao then walk back to her room.

However, Aoi noticed something's missing. "Um… Where's Shinobu-sama?" She asked.

Kanae later had a hint of sadness on her face. "Shinobu… She suddenly has a new mission to the north. She said that she want to enjoy the mission you see." She lied to ease Aoi's worries.

"I see." Aoi nod in understanding. "Then Kanae-sama, I'll prepare your room." She then run to the mansion to preparing the room.

After Aoi is gone, Kanae later take a deep sigh, glad that she manage to show little sadness on her face when she's facing with the other girls.

Sanemi surprisingly grinned. "You did well." He said. "For Shinobu no need to worry. I'll search for her and ask permission from Oyakata-sama about it."

"There's no need for that Sanemi." Kanae shook her head. "She's my younger sister. It's my responsibility to do so."

* * *

At the same time on Eiji's mansion, Shinobu is seen being chained up on a chair while still wearing her pink kimono. Eiji already ordered to confiscate her **Nichirin katana** and her Demon Slayer outfit and haori for a while.

However, the most surprising thing is that the one is investigating her is not Eiji, but Fujita, who sit on desk with a smirk on his face. Eiji is seen stand on the left side of his desk. "So Butterfly Girl let's begin the interrogation shall we?"

"I have a name." Shinobu said. She dislikes this old man attitude since what he said in the passageway. He gives a presence of someone that's used to kill people.

"But first. Let's begin by showing the eyewitness. Yes, another one that also known your illegal organization existence. Cho." Fujita called, completely ignore the complaint. Not long after, the door is open, and the other old man that talking with Fujita in the carriage known as Cho is entering the interrogation room.

"Hello young lady. I've never expect you're this beautiful." Cho greet Shinobu while teasing her.

Shinobu didn't reply to his greeting. She just look toward Fujita with narrowed eyes.

"Let's begin with the basic question shall we? The information will be keep on the eyewitness in this room." Fujita stated. "What's your name?" He asked.

"Shinobu Kocho."

"Your age and height?"

"14 years old and 148 cm."

"So you're another weasel girl huh?" He joked with deadpan look on his face.

Eiji sweat-dropped, remembering the time when Fujita called a certain girl weasel.

Shinobu however had a tick mark on her head.

"Put that aside. How many siblings do you have?" Fujita continued his question. "Judging from what Eiji told me, you have an older sister. Kanae Kocho am I right till' now?"

Shinobu nod.

"Let's go to the main question." Fujita stated before looking at her intently. "Do you know what rule that you disobeyed Shinobu Kocho?"

"Yes. Bringing a katana or other weapon in the face of public is violating the law that being set since the beginning of the Meiji Restoration."

"So you understand the law after all huh?" Fujita slightly mocked. "But… I not the type to judge too quickly. Let me guess… Oni."

Shinobu narrowed her eyes. "Even if I tell you, there's no way civilian will-"

"Do I look like an ordinary old man to you?" Fujita later stand up from his desk with a smirk. "I've already known the existence of Oni for a long time. Ever since I've become police inspector of the Meiji Era, I also spent my time hunt down all of them as many as I can. Even now still same, but… The big head, Muzan Kibutsuji. I've never seen him." He said, revealing his knowledge about Oni.

"I also the same little girl. During my time, Shishio-sama and the others sometimes kill Oni for sport." Cho join the conversation.

"That Muzan seemingly change one member of Juppongatana into an Oni to create a powerful group of his own." Fujita explain. "So butterfly girl… Tell me everything about Demon Slayer Corps if you may?"

Shinobu is speechless. How'd both of this person know the detail even Muzan Kibutsuji's name. For now, she suspects that Eiji know as well. "Who… Are you exactly?" She asked. "And you're known about Juppongatana? If that so, please tell me!"

"Why don't you discover it yourself, stupid." Fujita replied sarcastically. "Continuing my question, explain everything about Demon Slayer Corps that you know. If you not, I shall warn you that myself already killed several Demon Slayers and their Pillars during the Bakumatsu for siding with Isshin Shisshi. I usually caught one or two of them for information leaking but they never spill out the truth. "

"You… Killed numerous Demon Slayers…?" Shinobu asked in anger. "You killed the one that fight for humanity against them!?"

However, what she got is the former police inspector is making a laugh. Like he was expecting that answer. "Fool. So the leader is closing it to this generation… Just as I suspect." He said.

"That's expected isn't it? If any information about Demon Slayers Corps allied with Isshin Shishi during the Bakumatsu being leaked out, it will crush every morale of those who join them now." Eiji opined.

Shinobu immediately argued. "That's impossible! Demon Slayers is a neutral organization! Our code is to slay Oni behind the public eyes! There's no way during Bakumatsu they're allied with Isshin Shishi!"

"Still doesn't believe the fact?" Fujita asked her. "If I not wrong, all of your organization just filled with people that want revenge against Oni for killing your loved ones, thus must believe in killing a being- no, a superhuman with simple mindset of killing them for the greater good. But like I stated during that time… Once someone wield a sword taste any kinds of blood, it can never stop himself or herself from the way of murder." He explain the philosophy of the hitokiri.

"That just for the one that have cold heart and likes to kill! A sword can also be used to protecting others!" Shinobu argued.

"You really think so?" Fujita said with narrowed eyes. "No matter what kind words you used, the hard fact still remains. Sword is a killing tool, and every sword styles are an art to do it. That means, everyone who wield sword, even Eiji and Cho in here is not good people at heart. That kind of people are only existed in fiction." He stated. "If you wield a katana, you should remember this basic fact Butterfly Girl. To protect someone mean you must kill. And to let someone that's close to you lives, you must kill someone that threaten their lives. Fast or slow, if you can't control your desire to be the strongest, it will take you to be an assassin with no heart."

Shinobu can't retort for Fujita's words. All he speaks is the truth. Ever since she and Kanae wield a **Nichirin katana**, both of them known they will walk the path of murder. The difference is that they kill being that devour humans with no remorse. However, her meeting with Sofia and Spider Family starting to open her eyes to the truth that there are some good Oni out there that's forced to eat human and tried their best to fight against Muzan's influence despite she doesn't want to believe that fact.

"For that… I already know." She retort. "But… Fighting being like them it is necessary to be cold-blooded killer."

Hearing the reply, Fujita thought for a moment. 'Battousai. If you're here… I wonder what'll you say to this girl…' He thought remembering his old rival once again. "So from all those long words I can summarize that Demon Slayers exists since the ancient times, all of them make an oath never joining any human faction which is prove to be a lie during the Bakumatsu, and most of them are filled with swordsmen that filled with anger and even a child can join it if they wants. Which means, my investigation since the Bakumatsu is almost solved. That leaves where's Muzan Kibutsuji only" He sigh in relief. "Thank you for the information that you shared years ago, Cho."

"Thanks Shishio-sama for that. I'm only doing his order." Cho denied the thanks.

"And for you Butterfly Girl." Fujita said to Shinobu. "I'll be taking your katana. Your cooperation is over. You're free to go wherever you want."

"That's my sister **Nichirin katana**! You have no right to-"

"Tou-san." Eiji later holding Kanae's **Nichirin katana** on his hand, before giving it to Fujita. The former Police Inspector later receive it, before unsheathe it, revealing a pink shade on the sword.

"Hmm… Interesting. This maybe can be useful for some artifact; since I bet her older sister is the same as her." Saito commented at the **Nichirin katana**'s quality. "I wonder who's the sword-smith that making this?"

"Take back those words! You know nothing of her! You just a direspectful old man that loves to mock other!" Shinobu snapped.

"Is that a challenge to me?" Fujita asked while stand up. "Very well then. If you want your older sister katana to be return to you, defeat me one on one. How's that sound?" He challenged.

"Tou-san!" Eiji said in worry before turn to Shinobu. "Shinobu, don't accept his challenge please!"

However, due to her snapped mind of constant mocking, Shinobu gladly accept the challenge, completely underestimating Fujita's capabilities and ignoring Eiji's warning. "I accept it. I'll show you how strong a Demon Slayer compare to usual swordsman like you." She accepted the challenge. 'Huh, like an old man ever stood a chance. I bet he even doesn't know **Breath Styles**.'

* * *

The time later skip to the backyard of Eiji's mansion. Cho is seen watching the battle by leaning on a tree with interest, while Eiji standing between Shinobu and Fujita as the referee.

"Let me tell the rules. The rule are no killing allowed and the winner will be decided if one of you unable to stand or lose consciousness." Eiji explain.

Shinobu already unsheathe the katana, which is in fact Eiji's guntou. Fujita meanwhile also using the same guntou.

"Ah. Before the game of slaughter begin, it's not fair if I not reveal my true identity." He said. "My name is not Fujita Goro. It's a name that I used from Meiji Era till now." He then entering the same stance as the one he did in the passageway of Kyoto. "I'm the former leader of Squad Three of Shinsengumi, Hajime Saito." He said as suddenly, a faint aura that take the shape of a wolf's head is form around his body, prove that even on his old age, Saito Hajime never break his fangs and dedication to preserving Shinsengumi's principal judgement: Aku. Soku. Zan or Swift Death to Evil.

Hearing it make Shinobu a bit trembling. "Hajime… Saito…" She said in disbelief. "As the… Shinsengumi Third Unit Captain… Of the Bakumatsu…" 'First Juppongatana, Oniwabanshu, and now Shinsengumi… Why'd old groups of the past suddenly make many appearance? Could this man also know about Arata-kun?'

Saito received her response with smirk. "Rather than shudder in fear knowing your enemies reputation, I think you shall find a plan to take me down." He advise with sarcastic tone.

"Ugh." Shinobu grunted while picking her own stance, preparing to stab him.

"Begin!" Eiji declared.

Shinobu later dashed so fast that she disappeared from the scene.

'**Shukuchi** huh?' Saito analyzed as he still on his strange stance, looking for Shinobu's whereabouts.

"Eh? So she can do the same technique as Soujiro huh?." Cho observed in interest. "But… That still not reach the speed of Tenken at all."

Shinobu suddenly appeared behind Saito, tried to stab him, but Saito quickly doing a ground slash, knocking her off her feet to the ground. He then tried to stab her chest, but Shinobu managed to roll over before jump back to keep her distance.

'He's fast. That means I must use at least one of my technique... To incapacitate him by aiming his vitals.' Shinobu thought before preparing a stance. '**Dance of the Dragonfly – Compound Eye Hexagon**!' She then dash using **Shukuchi** once more toward Saito, who already prepared to counter. Using his already super speed, he tried as best as he can to block each of the stab, although still end up with four scratches: the left neck, right shoulder, left leg, and one stab almost hit his right eye. He then quickly jump backward. 'It only manage to scratch him!' She thought in surprise before keeping her distance once again.

"Nice stab. I can't believe a girl with short hand and body like you can do such fast and precise stab to each of my vital organs." Saito compliment with a smirk. "And I finally realized something. The pattern of your attacks."

Shinobu raise her eyes in confusion.

"The way your strike. Even though you strike with guntou, you only do two things. Stab and thrust. Using some strange technique called **Total Concentration Breathing** that I learn from many Demon Slayers that I've killed during Bakumatsu, you strengthen your physical to reach the realm of Oni. But why'd you never tried to slash me? The first attack is thrusting attack. The second is a series of rapid stab that targeting the vitals." Saito said, starting to display his amazing ability to analyze something very quickly. "The reason is to close your weakness. Your body actually pathetically weak. So you close it with the stab or thrusting movement that yourself created."

'He can predict it after two attacks! If Oni I understand because they silently can share information… But this man… Hajime Saito…' Shinobu gasps in shock.

"So how is it? I can predict what I said is true." Saito asked the obvious question with a smirk on his old face.

Shinobu didn't reply and she later preparing for her strongest attack. "I can't believe I must use this move against humans, but… There's no way you can escape the strongest technique of my **Insect Breathing**." She boasted before going into a stance to use the attack. '**Dance of the Centipede – Hundred-Legged Zigzag**!' Shinobu later doing **Shukuchi** in Zigzag, racing toward Saito, who preparing his trademark stance.

'**Hidari Katate Hirazuki**!' Saito later dash toward Shinobu, who appear suddenly in front of him to deliver a powerful thrust. Saito however, quickly changed his attack from thrust to upward side-way slash, deflecting Shinobu's thrust from his body and make his own guntou thrown to the air.

'Wh-' Shinobu unable to finish her thought as her body is being assaulted by barrage of punches from Saito, making she lost grip of her guntou before Saito finish it with an upward punch to her chin, sending her to the air while cough blood, before crash to the ground.

"So a zigzag movement of **Shukuchi** while tried to gain momentum for a powerful thrust that can even pierce a large stone is your trump card?" Saito asked. "A good technique but the times you doing those zigzag, you place too much power on your feet, making the ground cracked and your **Shukuchi** have a blind spot."

"That's right." Cho joined the conversation before walking toward Saito. "**Shukuchi**' is a good technique for straight ahead and curve movement, but lose its advantages if someone's doing a movement that need to stop first like zigzagging."

"Not… Yet…"

Saito turn to look that Shinobu's struggling to stand up. "Oh? For a weak body that's impressive endurance." He compliment.

"Not yet…" Shinobu said with determine look on her eyes. "I… Won't let you… Take my sister's **Nichirin katana**… I… Must become stronger. For that-" She later unleashed her hidden knife on her sandals. "I won't back down! Even if my enemy is Muzan Kibutsuji himself!" She then run toward Saito while unleashing battle cry before doing an upward slash with her left leg to injured him more. However, It is revealed that Saito managed to avoid the attack.

"Idiot." Saito later catches her left leg, which surprises her. "Due to slower movement and emotions that controlling that mind of yours, you're become easier to predict." He then tighten the grip on it, seemingly tried to crush Shinobu's left leg and making her grunted in pain. "However… The fact didn't change." He then releases the grip on her left leg, making Shinobu fall to the ground. "You run away from the goal you set just because your body condition. If you want to bark again, you should train more. Eiji." Saito later called the police officer. "Return her katana. I still respect her determination. Is more than enough."

"As you wish Tou-san." Eiji replied before pick Kanae's **Nichirin** that strapped on his waist and give it to Shinobu. "You did well Shinobu. Not many people can get Tou-san respect." He compliment her with a smile.

"Th-thanks… Eiji-jiisan. But I've never expected you're the adopted son of that famous Hajime Saito" Shinobu confusedly said before receiving the **Nichirin katana** later look toward Hajime Saito's back, who's walk away from the scene. So… This is the strength of one of the former captain of Shinsengumi, Hajime Saito. Although his strength surely become weaker like Mr. Urokodaki due to his age, he still manage to outclass me…' "Saito-san!" She yelled at him.

Saito stopped, to glance at her with a smirk. "What is it? Last time I remember few minutes ago, you're not used that kind of polite tone." He commented.

Shinobu take a deep breath before stating her decisions. "Saito-san… Can you please train me… Everything that you know about Shinsengumi's swordsmanship!? Please! Right now I need to become stronger to protect those dear to me! Forgive me for my harsh words! I've too swallowed by my ego dared to challenge legend such as you."

"Hoo…" Cho commented in interest. "What'd did you say Saito? She wants to train under you."

Saito slightly widen his eyes, before smiled. "Like I want to. Oi Butterfly Girl."

Shinobu then look at him.

"Bring me a Soba. You can buy it on the store that close in proximity with this mansion. After that, I'll consider your wish." Saito ordered.

"But this is midnight! The Soba shop is already-"

"Then wait until it opened. This talk is over." Saito completely closed the conversation as he walks away from the scene. 'A girl... Want to train under me? Huh, what a joke.'

* * *

The time later skip to morning. On Kanae's side, she already get up early from her bed and currently eating the breakfast that was made by Kiyo, Naho, and Sumi. Despite still 7 years old, the three of them are skilled enough to make basic food. Sanemi is also seeing enjoying the food that they create.

"Hmph! As always the food in here is very good!" Sanemi said in delight.

"Thank you so much Sanemi." Kanae thanked. "Will you go back today?"

"Yes." Sanemi replied. "I will talk about it to Oyakata-sama don't worry. If he's giving you few missions, you can spend your time to look for her." He assured.

"Thank you. But… I can't hope but feel that she's okay somewhere…" Kanae said. 'Kai… No need to worry. Like I said, two weeks, then I'll be back. I can't wait to see that you're manage to cure Rui and the others.'

* * *

Back to Natagumo Mountain, Rui is walk out from the temple, tried to go to the outside. When he reach outside, the surprising thing is that he's not burn to ash like most Oni. He then take a deep breath, feeling the fresh morning air after very long time can't do that.

"So Mr. Kai's effort really works out. Thanks to it, we're able to obtain our **Blood Demon Arts** while losing the ability to regenerate quickly, needs for human flesh, vulnerability against sunlight, and my connection to Muzan-sama." Rui said to himself while opening his eyes, revealing that his red sclerae turn into white.

Kai is seen watching on the entrance while leaning his body on one of the pillar. He now didn't wear his trademark mask as a part to getting closer to his new comrades. "So it work huh?"

"It seems." Sofia replied while walking toward Kai from inside the temple. "Chisaki-san. Thank you so much for freeing us from that monster. You will had my loyalty at your side."

"Don't thank me. Since you're faithful Christian, thank your god because all of our effort progress smoothly." Kai dismissed the thanks before walk inside the temple. "I plan to relax myself for now. Till' Shinobu and Kanae's back, all of you free to do what you want." He said.

**Notes:**

**That end the chapter. How could Rui and Sofia be able to walk during morning? That will be explain in two chapters from now.**

**As for Shinobu encounter with the older version of Hajime Saito, I already said that the elements and characters of Rurouni Kenshin will appear. I plan to make Shinobu learn Saito's Gatotsu and Hirazuki.**

**As for Shinobu VS Saito, I realize that Shinobu is slightly powerful than Saito, especially since this Saito is already mid-60s. However, Saito had something that he always relied on: An ability to control the flow of the battle against temperamental opponent. Since this version of Shinobu is when she's brash and straight-forward, she's easily to be controlled to turn the favor on Saito.**

**As for Mishima Eiji, he's Saito adopted son from Shishio Arc. Meaning he's Canon character.**

**See you in the next update! Be safe from currently spreading Covid-19. Decrease all activities on the outside, frequently wash your hands and keep your health in check to stop the spreading of the viruses. I hope all of you save from the viruses.**


	8. Chapter 8:Understand your Weakness

**/N: Boku no Hero Academia is written and illustrated by Kouhei Horikoshi. Kimetsu no Yaiba is written and illustrated by Koyoharu Goutoge. Rurouni Kenshin is written and illustrated by Nobuhiro Watsuki. I don't own the three of them.**

* * *

**How to read the story**

In the… – Normal

"You're…" – Conversation

'Why…' – Thought and telepathic communication

Kagune – Foreign words

"**Fired…"** – Deep Voice

**Tetsusaiga** – Technique, Quirk and special weapons

* * *

**Chapter 8**

**Understand Your Own Weakness**

On Kanae side, she along with Sanemi are currently walking to the main base of Demon Slayer Corps that is located not far away from the Butterfly Estate. Despite still grieving because of Shinobu's disappearance, the Flower Pillar must keep her composure as good as possible.

'The information that I've got till' now… My encounter with an Upper Moon Two and this mysterious groups that have connection to the Juppongatana, I must tell all of it in the meeting.' She thought before finally arriving at the Sakura Garden where Kagaya and the Pillars that can attend the meeting is seen. There are another three that appears to be available beside she and Sanemi.

The first is an extremely built and muscular man that having both of his eyes blind. He has spiky black hair and a prominent scar running horizontally across his forehead. He wears the black and white uniform typical of a Demon Slayer, with an olive green happi draped over his shoulders. He also sports a large-beaded necklace around his neck and carries ojuzu. This man is Gyomei Himejima, the Stone Pillar of the Demon Slayer Corps and currently hailed as the strongest among Pillars. He's also the one that saves Kanae and Shinobu when their parents is being killed by Oni, so both of them saw him as some sort of Older Brother figure.

The second is a young adult of tall stature with bright yellow hair with red streaks, black forked eyebrows, and golden eyes. His outfit consisted of the regular Demon Slayer uniform along with a white-yellow gradient pattern and red flame-like ridges at the end. This man is Kyojuro Rengoku, the Flame Pillar of the Demon Slayer Corps and one of the most hot-spirited of all Pillars.

The last is a young man of short stature and a pale complexion. He has straight-edged black hair of varying lengths, the longest reaching down to his shoulders and the shortest stopping at his cheekbones, which he wears down with two shorter strands hanging between his eyes. His eyes are almond-shaped and tilt upwards on the far sides, and are unusual due to possessing heterochromia—his right eye is yellow and his left eye is turquoise. He wears a navy blue version of the standard Demon Slayer uniform, along with a black and white pinstriped haori, the hem and cuffs of which are striped length-ways rather than vertically, which covers his hands. He also sports bandages in place of the leg-wraps around his calves, as well as another set of bandages that cover his mouth, and blue-strapped zori on his feet. He is also seen with his white snake wrapped around his shoulders. This man is Obanai Iguro, the Snake Pillar of the Demon Slayer Corps.

"You take too long Kanae. Oyakata-sama already waiting for 15 minutes." Obanai greet her.

"Hello Kanae! I'm glad you safe!" Kyojuro greet enthusiastically with his usual high-spirited tone.

"Kanae… I'm glad you're fine." Gyomei greet her.

Kanae nod with a smile. "Hello Iguro, Rengoku, Himejima-san. I'm so glad that all of you in great health." She greet them back. She then look toward Kagaya before kneeling in respect. "My respect for you Oyakata-sama. I'm sorry for making you worry for few days." She said.

"It's okay Kanae. I'm also glad that you manage to return safely. All of us afraid that you and Shinobu is being killed." Kagaya replied with kind tone.

"My respect to you Oyakata-sama." Sanemi greet him while kneeling in respect.

"Thank you Sanemi." Kagaya thanked him before starting his speech. "Now then, before we begin I'm pretty sorry for this sudden meeting. As I expected, not all of the Pillars can attend the meeting since they are busy in their each assignment. However, this meeting is based on Kanae's request. She had something important to said to all of us. For that, I thank you for the Pillars that can attend this sudden meeting." Kagaya explain.

"Thank you so much Oyakata-sama." Kanae thanked him. "Like he said before, I'm sorry for interrupting the time of anyone in here. However, the information of mine is important to be known by the Demon Slayer Corps. During my investigation on the Northern District along with Shinobu, I've encountered an Upper Moon. In fact, Upper Moon Two." She revealed.

After hearing what she said, the existing Pillars cannot hide their shock. The encounter with an Upper Moon is a guaranteed death even for Pillars if they're alone, since they're six strongest Oni below Muzan Kibutsuji himself and had the strenght equal to three Pillars of the Demon Slayer Corps. For hundred years, no Demon Slayers can't kill an Upper Moon.

"But… You still alive… Did you kill it?" Obanai asked, clearly not believing that Kanae come out without any injuries.

"Unfortunately no." Kanae immediately replied. "I was fatally injured by his attacks, but I manage to drag the battle until sunrise when he's force to retreat. Luckily, one of the villagers in there manage to treating my injuries, saving me from certain death." Kanae said, remembering that Kai is the one that saved her despite it had a motive for it. "I can't thank him enough."

Kagaya seemingly interests by this information, especially about the Upper Moon encounter. "Since you fighting this Upper Moon, Did you know about his appearance?" He asked.

"He appears to be a young man with rainbow-colored eyes. His rank is Upper Moon Two. He had bloodstains on his head and speaks in a carefree, gentle manner. He using a pair of sharp iron fan as his weapons and his **Blood Demon Art** is ice-based." Kanae explaining the appearance of the Upper Moon Two before revealing his name. "He goes by the name Doma."

"Doma? I see. If that so, finding this Upper Moon Two will be our top priority since no one that sees an Upper Moon lives to tell the tale." Kagaya stated. "If an Upper Moon is in there, maybe Muzan is close in proximity to that village."

"For that I still not know Oyakata-sama." Kanae replied. "But this second information is important much than the first."

"What kind of information is it Kanae? You encountering an Upper Moon is already worried us enough." Gyomei asked.

"During my time of investigation, I've encountered a swordsman that can outlast me long enough with little injuries and even manage to slashing my right shoulder." Kanae beginning her explanation, hiding the fact about his encounter with Kai, about her and Shinobu that's forced to join the Shie Hassaikai, and the event of Spider Family. "He's a part of the group that claiming to targeting you, Oyakata-sama."

"What!?" Obanai lose his composure for a while.

"Who the fuck that dares to targeting Oyakata-sama!" Sanemi immediately furious hearing it.

"It's hard to believe Kanae! Who's this swordsman?!" Kyojuro asked.

"I don't know. But there's one hard fact that's hard to believe." Kanae said. "All of us know that if someone mastering **Total Concentration Breathing** no matter how weak they are, we know that all of us considered a superhuman right?"

What she said receiving a nod from all of the participants.

"This young man that I battle with, manage to go on equal footing even outclass me in speeds… Without using any kind of **Total Concentration Breathing**." Kanae revealed.

"That's absurd if I must say Kanae. If low-rank member I can understand, but you're Pillar. There's no way a normal swordsman who doesn't use any kind of **Total Concentration Breathing** can-" Obanai said in disagreement before being cut off by Kagaya.

"Or maybe… He only using the basic **Total Concentration Breathing** that every swordsman used. Not the advanced one like us do." Kagaya theorized. "If we trace back, **Breath Styles** doesn't belong to our organization alone. There are also swordsmanship that requires basic **Total Concentration Breathing** as well."

"That maybe the case. But the groups that he's affiliated with is what scares me. He said his group name to be reborn Juppongatana." Kanae continued.

"Juppongatana?" Sanemi said in confusion.

"I've never heard such name before!" Kyojuro said in confusion as well.

"What kind of group with that name?" Gyomei uttered while his hand and forehead showing vein of suppressed anger. "I wonder why they're targeting a kind person like Oyakata-sama…"

"I don't know much the detail. But from his words, the organization plan to kill Muzan first, then us the Demon Slayer Corps, then they are planned to take over Japan and changed it to their own image." Kanae informed every bit of information that come out from Arata during their battles.

"Juppongatana... I see, if that is true this is a very bad situation. We already have our hands full at taking care of Oni, but I've never expected the human that we're tried to protect is targeting us. From what I get from Kanae's explanation, they seems plan to attacking us because afraid we'll disturbing their plan of rebellion." Kagaya said in confused tone for the first time while trying to analyze each of the information he received. "However… I know a little about them even though the previous Meiji Era is disclosed all of the information of them due it can cause panic to entire Japan on that time. It is a group of terrorists with the intention of overthrowing the Meiji Government during the early years of Meiji Era. It was filled with bloodthirsty assassin, samurai, and many others. Their leader however, is a different scale than most of its members. A hitokiri, from what the leaked news that my great grandfather managed to get. He said is an abnormal human that still alive even after have his body being burned and his head being shotted by a gun. His name is... Makoto Shishio."

This earn a surprise from the attending Pillars. No matter how strong human become, head is always the fatal strike. A headshot mean instant death. But hearing the leader of Juppongatana is still alive after being burned and head-shot is something like only an Oni can.

'That's impossible!' Kanae thought while her face clearly surprised. Although she already knows a little due to Rui, this is something that's unexpected. "Makoto... Shishio?"

"That's impossible!" Kyojuro denied it.

"That something not normal. To think a human can still be alive after all those kind of injuries… Not even Demon Slayers can be alive after an injuries like that…" Obanai wondered. "If it's Kanroji, I can understand but this Makoto Shishio... Sounds more like an Oni to me."

"He's a Hitokiri? That means he's a human that enjoying killing other humans right? Sounds like an Oni to me!" Sanemi said with a hateful tone. "As I suspect, the humans during that time enjoying killing other humans!"

"You can't judge them like that Sanemi. Many Hitokiri during Bakumatsu is allied to two factions: Either they are Yoshinobu Tokugawa or Isshin Shishi. They have their hands in building peace in the new Japan despite their dirty works. For example, the most famous hitokiri during the Bakumatsu: Hitokiri Battousai and the former Wolf of Mibu: Hajime Saito." Kagaya said to Sanemi. "Okay then. All of you can dismiss and go back to each of your tasks. But Kanae, I want you to stay in here for a while. It seems you had other things to tell."

After Kagaya nod to Kanae; Gyomei, Sanemi, Kyojuro, and Obanai are leaving the mansion.

After the others is gone, Kagaya then smiled to Kanae. "Then Kanae, what other think you going to say? There's no one here but me now so you can speak freely." He asked kindly.

"The truth is…" Kanae then look toward Kagaya with firm look on her face. "Oyakata-sama, I want that my mission is being reduced for a while. You must be already know but Shinobu is not return here with me. She's running away…" Her face later turn sad again.

"Running away? I see. That's why your face is not as cheerful as usual. Very well, I know how important Shinobu to you since both of you had a very strong sisterly bonds. I tried as best as I can to tell the other Pillars to covering your assignment for a moment. But if I may ask, why'd Shinobu did that?" Kagaya asked.

"I… Truly don't know why. She leaves me a letter saying that She must become stronger so she won't become burden. But… That's not Shinobu that I know." Kanae said while unable to hold her tears.

Kagaya expression later turn sad as well, as if he understand how the Flower Pillar feelings right now. "Don't cry Kanae. I also sad if one of my children is also sad." He said.

Feeling Kagaya's kind words, Kanae feel at ease. She then rubbing her tears away. "Thank you very much Oyakata-sama." She thanked.

* * *

Back to Shinobu, she still staying on Eiji's mansion. The young Kocho still tried to convince the former third unit captain of the Shinsengumi: Hajime Saito, to train him. But no matter how hard she tried, the Wolf of Mibu always declined with his trademark smug face.

"Saito-san! Please!" Shinobu said to Saito as he's busy making a Soba that she buys this morning. True to what Saito said, she must till' morning until the seller opening the shop.

Saito later sigh. "Surely not giving up are you not?" He commented. "Go away. Although I'm thank you for the Soba, the sword-art for killing is not something a young girl like you must learn. Search for another teacher that want to teach you kinder swordsmanship." He said rudely.

"But who!?" Shinobu raise her voice. "Eiji-jiisan is gone to his office while Sawagejo-san is gone to somewhere I even don't know where! The reason I stay in this home is to avoid any of the Demon Slayers to find me. Please train me! If what I said that night make you upset… I-I-I'll do anything you ask!?"

"Even if you apologize to me, I won't train you since I already forgive you. The words from youngster isn't something that should be take to heart. But the reason is not because you denied the true nature of swordsmanship." Saito denied her apology. "Although I know from Eiji that your family is a skilled pharmacist, I still don't know why'd a girl that only fourteen years old decided to hold a tool for murder? I ask again, is it based on your hatred against Oni?" He asked, still curious about her reason.

Shinobu narrowed her eyes. "Like a Shinsengumi who kills on the order of Shogun can understand what I've been through…"

"I see. Your family is being killed by an Oni then." Saito guessed.

"For an old man you surely not have any attitude." Shinobu tried to controlling her anger. "You keep reading my mind... Is rude!"

"I have an attitude, but I've never thought I can easily reading the mind of a swordsman before." Saito said with a smirk on his face. "You still can't beat me and yet you want me to train you? Don't make me laugh. My technique is not something that I easily passed on to someone else. And… To gain it, you must not only kill Oni, but human as well."

Shinobu however won't give up until Saito want to train him. "What shall I do to make you want to train me?"

"Hmm… Maybe kill some corrupt people?" Saito guessed with a mocking tone.

"You… Even I will do anything, there's no way I use my **Nichirin katana** to kill human that I wish to protect!" She denied what Saito asked her to do.

"You already know the hard fact that human also can become as evil as Oni. Yet you decided not kill them? What a joke." Saito a little amused by her naive way of thinking. "Very well, I'll train you, If only I can enjoy my old time without hearing you noisy voice, Butterfly Girl. Meet me on the dojo room at nine o'clock."

Hearing that the former Shinsengumi captain want to train her bring sparks to Shinobu eyes. She never believed that Saito finally agreed to train her. "Thank you so much!" Shinobu said while bowed in gratitude.

"Now get out Butterfly Girl." Saito ordered her. Shinobu later got out from his room. After she's gone, Saito hummed to himself. "Seemingly I got another student huh… However, the biggest challenge now is not if he can master my technique or not. But to battling something more important than that…" He uttered to himself.

* * *

The time later skip to dojo room inside of Eiji's mansion. Shinobu already changed her outfit to her Demon Slayer outfit. However, she waited for half an hour until Saito finally enter the room, using a karate clothes.

"Well then, let's begin the training." Saito stated while cracking his fists.

"Um… Where's you guntou Saito-san?" Shinobu asked. Maybe he's old so he forget it?

"Oh yes. I almost forgot." Saito slightly widen his eyes. "Put your sword away."

"Eh?"

"I said put your sword away." Saito ordered. "Since you want me to train you, you must listen to everything I say from now on."

Although wanted to protest, Shinobu obeyed and put her guntou on the floor before facing against Saito. "So… A hand to hand combat?"

"Since you already wield a guntou very masterfully despite your weak body, I presumed you at least learn basic hand to hand combat right?" Saito asked.

"I-It's not like I learn… But my body won't allow me to do a strong hand to hand combat…"

"I see. If you keep cursing your own weakness, there's no way you can become stronger." Saito noted. "As I expected, a runaway dog is a runaway dog huh?"

Feeling little insult by Saito's words, Shinobu tried her best to hold her anger. She knows from her first fight that Saito is the type that using his enemy mentality problem, able to read their inside through small exchange of words, change in breath, and body posture. He's truly a force to be reckoned with. Not surprising that he kills many Demon Slayers and Oni during his active time as Shinsengumi and Police Inspector. 'I won't fall for that again! You're just like Chisaki!'

Saito later drop to the same stance he show during his fight against Shinobu, but this time without using his guntou.

'That's **Hirazuki**!' Shinobu later preparing a stance as well. "It seems you can use those stance without a guntou."

"Better try to dodge it fool." Saito later dash toward her using an amazing speed, aiming to punch her face. Before the punch can hit, Shinobu manage to dodge it to the right side.

'She dodged that!?' Saito thought in surprise.

'From the stance you show in the alley and the backyard yesterday, I understand something. You're left handed, so you prefer to using your left arm, meaning that your right side is openly exposed!' Shinobu analyzed while making a direct punch to Saito's stomach, making the former Shinsengumi stumbled back. "Seems I've land the first punch."

However, after stumbling backward for a while, Saito is seen chuckling. "Khu khu khu. Nice punch." He praised while he look at her with a smile, still touching his hit stomach. "You truly fit for your position as a Demon Slayer."

'That had some effect on him. His age is making his durability lowered.' Shinobu thought while a bit surprised that Saito manage to recover quickly.

"Well then, I think it's enough. From what I saw, you fit the qualifications." Saito noted that Shinobu's passing the test of hand to hand combat. "Let's go to the backyard."

* * *

The scene later change to the same backyard that Saito and Shinobu used to fight before. Both of them now carrying their guntou.

"Now then. I'll explain the moves I've used before, since you already seen it two times. It was called **Hirazuki**. I believe you already know Hijikata Toshizou don't you?" Saito asked.

Shinobu nod. "The commander of Shinsengumi?"

"That's right. The reason he created this move is for one purpose: To kill any opponents quickly and effectively. However, you must take a specific stance like I use before to maximize the attack. The beginner mostly can do thrusting attack using it, but Hijikata, me, the second captain Nagakura Shinpachi, and the first captain Okita Souji able to develop it by changing it to sideways slash during the charge or creating our specialized attack using **Hirazuki** as a base." Saito explain while smoking. "Before I teach you my special moves, I want you to master **Hirazuki** first. I think that's easy lesson right?"

"Actually, I based my thrust on your **Hirazuki**. Maybe you already read it during out first clash Saito-san, but my arms are so small that it lacks slicing strength. My body is also short and because of that, I'm lack any strength from my arm for slicing attack. I can using powerful thrust but I can't even decapitate an Oni or human's head. For that, I close it using a mixture of poison on my **Nichirin katana**." Shinobu explaining her body weakness.

"I see. Let's work for that weakness first shall we?" Saito then pointing his finger toward two trees on the backyard. "You see two trees over there. Now I want you to using your technique that you show to me last night to cut that tree off." He instructed. "I bet you can do that."

Shinobu nod, before preparing stance for her current strongest technique of the **Insect Breathing**. '**Breath of the Insect: Dance of the Centipede**-' She then disappeared from beside Saito, using her amazing speed. '-**Hundred-Legged Zigzag!**' She then pierced the tree using her guntou, creating a huge hole on it before the tree finally collapse to the ground.

"Hoo." Saito's impressed by her handwork. 'Her thrusting technique, although only partially I can see a **Hirazuki** behind the initiation of the attack. She's truly training her thrusting technique to almost the limit of her body. However, there's great weakness in that.' Saito analyzed. "Huh. For someone who always curse your own body, that's pretty nice thrusting movement. So what I predict that night was right. You said that your arm is weak, but it seems there was a mistake in your statement." He commented.

"No. What I said was right. That technique of mine, although had a great destructive power, I must deploy it from long-range. What I use is only the momentum of the attack to maximizing my thrusting power. If I do that from close range, the technique will lose is effectiveness." Shinobu admitting her technique's flaw.

"In other words, the weakness is that you need a momentum huh? Let's work to fix that then." Saito stated. "But before that, I'll show you the technique of mine that I've planned to teach you." Saito later dropping to his unusual stance. '**Gatotsu – Isshiki.**' He later dash toward the tree with amazing speed before delivering a powerful thrust with his left arm, completely make a large hole in the tree while Saito is passing through the hole. He then look toward Shinobu. "This is the technique that I'll teach you. It's called **Gatotsu**. This technique relies on the strength of the upper body, lower body, and arm to creating a powerful thrust that can pierce through anything it touches."

'Using all three points at the same time! Now I see the flaws of all my thrusting technique are one. Although faster and more precise on target than Saito-san, my thrusting power is only relied on the arm power. In addition, for the **Dance of the Centipede**, I use my feet power as well so it created the same destructive power as the **Gatotsu**. I've never using any of my upper bodies power.' Shinobu's thought deeply about all of her techniques.

"So you found it then. You're done well enough with arm and leg, for that I'm pretty assured. What you lacking is the strength of shoulders and your upper body to facing the stress of slicing something. In addition, this **Gatotsu** is an impossible technique for you to learn. Your upper body can be destroyed during the dash or the good scenario is, you'll never be able to wield a sword forever and enjoy your life as a normal woman should. The same case will happen if you switching from thrusting movement using sideways slash when using **Hirazuki**. Are you prepared for something like that? If you back down, I won't deny it since you understand your body more than I." Saito warned.

Shinobu swallowed every words that the former Shinsengumi said to her mind. This training had severe risks. Plus, with no Kai to heal her using his Quirk-

No, she shakes those thought off. It is time for her to stand on her own two feet.

"Saito-san." Shinobu look at him with eyes full of determination. "I already determined myself to become stronger so I can protect those who are dear to me. I won't back down and face the risks you stated before."

Saito narrowed his eyes. "Interesting answer." He stated. "Don't blame me if your body can't handle it."

Shinobu nod.

"Then, I'll give you half a year to discover the way to strengthen your upper body." Saito said. "However, the way you do that must be discover by yourself. But before that, I bet you want to ask something about Juppongatana and their seemingly reborn group am I right?"

Shinobu sighed. "You read me again didn't you Saito-san?"

Saito letting out a smirk. "You're too easy to read. A girl is not supposed to hold a sword after all. Work on that as well." Saito jokingly mocked her. "Now then, if you want to know more about Juppongatana, go to the same room I've stayed before."

"Okay Shishou!" Shinobu replied.

* * *

Few days had passed on the Butterfly Estate, Kanae is seen sitting on the balcony. She's seen still saddened because of Shinobu's decision to train and leaving her. Even after she's searching the closest town and village to the estate, she always left empty handed without any clues about her dear younger sister.

True to his words, Kagaya is make her vacant from any mission for a while so she can focused on searching Shinobu.

Which is a fact that every girl on the estate realized. However, despite realizing it, none of them dares to interrupt her personal space.

However, Aoi suddenly ran toward her. "Kanae-sama." She called her while running toward her.

Kanae later turn to look at her. "What is it Aoi? You seems panicked of something…"

"The daily newspaper Kanae-sama." Aoi later present the front news. "Look at this!"

Kanae then reading it before widen her eyes at the news title.

**A young fourteen years old girl captured in Kyoto wielding a katana. The sign of the Samurai Second Rebellion?**

After reading it, Kanae can't help but realized who's the girl that's being mentioned on the news.

'Shinobu!' "Aoi, I'll go once again. Take care of the Butterfly Estate if the others is injured okay?" Kanae instructed her.

"Eh? O-okay. You can leave it to me Kanae-sama." Aoi stuttered.

Kanae quickly stormed off to her room, preparing her belongings. 'To Kyoto! Don't worry Shinobu, I'll come there!'

* * *

Meanwhile on Natagumo Mountain, Rui is seen standing alone on the temple's main room. There are many threads that's located in the room. In fact, it was his own.

He is training against Kai, who already in battle stance.

Making the first move, Rui swing both of his hands sideways to make the threads that he prepared raced toward Kai with amazing speed. He then jump to the air.

Kai however is prepared by raising an **Earth Wall** to protect himself, making the threads cut through the wall instead. He then counter-attacks by sending **Earth Spears** that's morphed on the tip resembles a drills toward the former Lower Moon Five.

'You maybe strong, but you always attack using the same spike pattern. Then, if someone's closing you, you quickly dispose of them using your special power.' Rui analyzed. "That pattern, I already read it!" Rui stated as he cut off all of the **Earth Spears** using his threads. From his feet, he kick upward, releasing five sharp strings from his feet toward Kai.

"Hmph. You're the same Rui." Kai stated as he jump sideways to avoid the attack. 'However, he's right. Currently, I too reliable to short-range combat. Maybe because in that sick world, I rarely fight those who had long-range type Quirk. But, I still can destroy your strings using my Quirk!'

"**Spider Web Formation**." Rui later forming his thread in form of spider webs before launch it toward Kai.

"Mistake." Kai later using his **Overhaul**, destroying all the threads when it make contact with his fingers.

However, Rui revealed it was a diversion to making Kai's attention focusing on his attacks. Using one of his threads as a launcher to delivering a punch straight to the Shie Hassaikai's leader face, making him thrown backward before he managed to stabilize himself using back-flip.

Kai later stand up, cleaning some bruises on his face. "Well, that's enough for now. Still, you are quickly progressed much than I've thought Rui. Even after I took the need to eat humans from you."

"This is fine." Rui replied. "However, since me and the others managed to walk under the sun once again, our movements must be strictly limited. Muzan-sama wish is to be able to walk under the sun once again. Lucky he can't read our situation right now because the cells that he used for it already being removed."

"I see. As a former most loyal subordinate of him, did you know what he's seeking to gain that desire?" Kai asked. This is getting interesting. A coward, easily angered lord build a huge amount of Oni for such little goal of gaining immortality and petty ability to walk under the sun? He's glad that he turn one of his loyal subordinates against him.

"It was a mystical flower called Blue Spider Lily. It said by him that if he ever eat the concoction of that flower, he can gain the ability to walk under the sun once again. He also promised to give us that flower as well if we ever fulfilled that mission." Rui replied.

"And then I wonder if he needs a cure." Kai commented. "Did you ever wonder when you become his loyal dog Rui, Why'd he gather so much people for such a simple goal?"

Rui shook his head. "Muzan-sama is different than you. He is controlling all of us through fear and threat. I've remember during one meeting that he didn't like to be questioned or corrected in any way and immediately kill the Oni that did so. If you want to say, he saw himself like some kind of God." He explain. "He never explain his personal reason at all. Each one of his subordinates life is based on his mood. We must follow his orders. Every words of him is absolute."

'Hmm… This is harder than I've thought. Muzan maybe a coward and temperamental child, but life for over thousand years surely make him intelligent and crafty. But, let see how intelligent he is… When I meet him face to face.' Kai thought while in his mind, a sinister plan is form to dethrone Muzan once and for all.

**Notes:**

**And that's for Chapter 8. Sorry if the chapter is too short, because I've prepared the chapter 9 for the clash against siblings.**

**As for Shinobu's strength, I read it in the Kimetsu wikia and stated that her thrusting strength is equal or surpassing Gatotsu in strength, being able to destroy a stone boulder and tree in half. But I read Kimetsu manga and watch the anime, and from what that I saw, Shinobu hold the amazing advantage in speed, I even said that her speed is only surpassed by Zenitsu. However, if look at the wikia again, I think what Shinobu lack instead of her arm strength is her weak shoulder and upper body. For that, her training will be focusing on strengthening her upper body.**  
**As for Kai, I had a plan for him to contact and fool Muzan. What kind of relationship that he will make with the Demon Lord? Wait and see.**

**See you in the next update! Be safe from currently spreading Covid-19. Decrease all activities on the outside, frequently wash your hands and keep your health in check to stop the spreading of the viruses. I hope all of you save from the viruses.**


	9. Chapter 9:Swallowed by the Plan

**/N: Boku no Hero Academia is written and illustrated by Kouhei Horikoshi. Kimetsu no Yaiba is written and illustrated by Koyoharu Goutoge. Rurouni Kenshin is written and illustrated by Nobuhiro Watsuki. I don't own the three of them.**

* * *

**How to read the story**

In the… – Normal

"You're…" – Conversation

'Why…' – Thought and telepathic communication

Kagune – Foreign words

"**Fired…"** – Deep Voice

**Tetsusaiga** – Technique, Quirk and special weapons

* * *

**Chapter 9**

**Swallowed by the Plan**

As soon as she read the newspaper that given to her by Aoi, Kanae already finish preparing to go to Kyoto. The older Kocho sisters already bring her new **Nichirin katana** in case that Oni will appear on her journey. She currently bid her farewell to Kagaya, who initially did not expect that the police would act like this. She then bowed in respect.

"Oyakata-sama, I now bid farewell to search for Shinobu. Apparently she's being captured and imprisoned by the polices in Kyoto." Kanae said. "But it's a little strange though, usually the polices will let us go away after asking us few question. I wonder why'd polices in Kyoto acts differently?"

"I also didn't expect this unless… Maybe there is some polices that already known the existence of Oni. Because no matter if they believe or not, some of them must be brave enough to investigate it on their own." Kagaya opined. "I pray for your safety Kanae. Be careful on there."

"Thank you Oyakata-sama." Kanae thanked before stand up and leaving the garden.

"By the way, since she's worried, she'll accompany you on your journey." Kagaya informed.

"She?"

"Kanae-chan!" Suddenly, a young girl is running toward the estate and hugging Kanae. She's a curvaceous young woman with fair skin and round, light green eyes with notably long eyelashes, a small mole beneath each of them. She has long, pale pink hair that fades into a neon green color at the halfway point, which she wears in three thick braids with five shorter clumps hanging over her face as bangs. She wears a modified version of the standard Demon Slayer uniform; the breast area is left unbuttoned to accommodate her chest size and she wears a short skirt in place of the usual hakama, and a plain white haori. As well as this, she wears a pair of navy blue thigh-high socks, over which she also sports the striped lime green socks and pink laced footwear. "I've heard that you're disappearing for many days! I'm so worried when Iguro-san inform it to me!"

"Mitsuri." Kanae called the young woman that is revealed to be Mitsuri Kanroji, the Love Pillar of the Demon Slayer Corps. She then returning the hug before releasing it. "I'm so glad you're fine. So how is it? Did you find any suitors that suits your taste?" She teased.

"Kanae-chan!" Mitsuri huffed. "You're so mean!"

"I'm just joking Mitsuri." Kanae assured. "But did you fine with it? I mean because this is my own problem and you probably still had other missions on your assignment areas."

"How can I leave Kanae-chan when she's wallowing in sadness because of Shinobu-chan is missing?! When I heard that Kanae-chan is sad, I can't stand it at all! As my duty as a Love Pillar, I must bring love back to Kanae-chan as well! After all, I'm also close to Shinobu-chan!" Mitsuri explaining the reason. "For that, I already had permission from Oyakata-sama to accompany you every time you want to search Shinobu-chan. Is that right Oyakata-sama?"

Kagaya smiled seeing her children antics. "That's right Mitsuri. Then I hope you can bring Shinobu safely. Because she's my children as well. Take care on your journey. There is a train that head-straight to Kyoto this morning. If both of you ride on it, you'll reach Kyoto at midday."

"Thank you Oyakata-sama." Kanae thanked while bowing in respect. Mitsuri also does the same. "Then, We'll take off now."

Kagaya nod. "Be safe both of you."

* * *

"Ah, I'm glad that all of you come. There's something that I want to discuss with all of you."

Back on the new Shie Hassaikai base on Natagumo Mountain, the old temple now looks different. It became cleaner and there are no plants that grew on its roof. The interior also looks the same. Now it starts to resemble the inside of the old Shie Hassaikai. On the main hall that now turn into a meeting room, Kai seen sitting on a self-made chair using his Quirk. By the looks of his face, he seemingly happy about something. On the now clean wooden floor; Rui, Sofia, Aiya, and Haruki is seen sit facing him. Since Kai is curing them using some kind of methods of disassembled their cells via his Quirk, there are some change now on their appearances.

Rui's appearance had change slightly, with only his eyes now change to blue pupils and white sclera while his other appearances remains the same. However, the most recognizable change is the loss of Kanji Lower Moon Five on his left eyes.

Sofia meanwhile had her hair changed back to her foreign blond color. The red dots on her face are also disappeared and her eyes change to purple pupils and white sclera. Her skin is still milky white though.

Aiya appearance is on her true form, a small child around the same age as Rui. Her skin has lost its two maroon lines on each of her cheeks and her eyes changed into maroon color with normal pupils. She also wore her short, black hair parted to the side with bangs framing her face and two, low pigtails.

Haruki appearance however is the one that drastically changed. Instead of white, her hair turn into black in color and now is short in contrast to her long hair. Her skin also turn pale instead of milky white and her changed to red color with cat-like pupils and white sclera.

Kai then continuing his talk. "But before I go to the talk, how was all of your body after the disassembling of Muzan's cells inside?" He asked.

"I-it a-actually feels good…" Aiya admitted.

"Like some part of us that being chained is being lifted." Haruki expresses her opinion.

"I must say that walk under the sun once again is really convenient." Rui said.

"However, this brings danger to us and especially you Chisaki-san. If this ever reach Muzan's ears, he'll definitely come here and ask you to grant him his deepest desires or consuming one of us to gain immunity to the sun." Sofia warned.

"Like I don't know that." Kai replied. "Muzan… I'm pretty sure I'll make him out from his burrows but for now, I'll explain what I had done to all of your body."

The remaining Spider Family then listening to it intently.

"First of all, thanks to my experiment on Sofia's blood with the help of her, Shinobu, and Rui as the first tested subject, I conclude something that'll benefit for us if we want to recruit other Oni to our group." Kai begin his explanation.

"R-Recruiting other Oni!?" Aiya shrieked in fear.

"B-but they can be more violent than us!" Haruki warned. "You never told us this before!"

"If I can, I'll stop him. But he's the one that will not back down that easily, even if what he aim is to recruit one of the Twelve Demon Moons. The recently leaving Demon Slayers also known this as well." Rui defending Kai's intention. "Besides, he's from the black side of humanity. Of course he more fit to recruit the evil ones."

"Like Rui said, I don't say that because of bluff but because I found out the properties of Muzan's cells that can become our ways to recruit them. Sofia, you may show it." Kai ordered.

Sofia nod, before showing something from behind her. It was a pack of experimental tubes with liquid of different colors inside. She then give it to Kai.

"Thanks." Tap his hand to the floor, it slightly lifted; bring the experimental tubes close to him. "Now as all of you can see, there are five liquids in here that was in fact Sofia's blood that have Muzan's cells in it. There are five different colors: red, blue, yellow, green, and purple. Now I'll explain each one of them." Kai then pick the red-colored liquid. "This liquid is filled with Muzan's cells that is dedicated to make the one that received it, including him must have the urgency to eat human flesh. In other words constant hunger to eat nothing than it. That cell is already completely destroyed from all of your body. You can now switch it to eating normal food like us humans." He said.

"So that's why I'm not feel hungry anymore when I saw human like Kai-sama and those two Demon Slayers…" Haruki uttered. 'How versatile that ability of his?'

Kai later pick the blue colored liquid. "This one is the cells that make you vulnerable to sunlight. When these cells sensed the UV from the sun, it will immediately turn to ash. The reason that all of you are able to walk under the sunlight once again is because I've remove this one." He explain.

Sofia then raise her hands. "Um… What's UV?" She asked.

Kai sigh. He forgot that the knowledge in this era is still backwater compare to his. "UV or ultraviolet light is the light that's emitted from the sun. More explanation will take longer so I tell the basics for now. Is that enough?"

Sofia slightly nod.

Kai then pick the yellow liquid. "This one is the cells that used for all of your abnormal regeneration. It seems connected to the blue one so as a consequences of making all of you able to walk under the sunlight, it also makes your abnormal regeneration gone. However, all of you may still recover faster than normal human like me, Kanae, and Shinobu."

"But I think there's another minus thing am I right?" Rui guessed. "You must be known that the more humans an Oni consume, the stronger we becomes. That's an absolute rules. However, since we can't eat human anymore, it means that we can't increase our strength."

"When did I say that because you can't eat humans anymore, your strength become stagnant huh?" Kai demanded. "Only a narrow-minded fool that thinks like that. Even now, I already see what each of you lack." He stated before pointing at Rui. "Rui. Your **Blood Demon Arts** are strong but that's it. You're too over-relied and put too much confidence on it and abandon any kind of fighting styles to closing the weakness of yours."

Rui narrowed his eyes at the statement, but realized what he said is hit the mark. "I… Admitted that." He uttered.

"As for you three: Sofia, Aiya, and Haruki. Due to many cells properties removal, your **Blood Demon Arts** is also lost since all of you originally get it from Rui. However, I also deduced each of your personality that must be fixed." Kai then point to Aiya. "You must fix your confidence. I had no need for coward in my groups." He stated rather harshly. While Kai is not like Kanae or Sofia. He bluntly expects more of his new Shie Hassaikai.

Hearing it make Aiya shrieked in fear while bow down. "F-F-Forgive Me!" She begged.

Kai sighed. If not because he respecting Sofia's promise, he would dump her already. "There's no need." He replied before pointing at Haruki. "You're too obedient and coward in battle. Maybe obedient to your Master is good in some situation but I can see something from your gesture. You're prepared to betray us if what that we did is not in your favor am I right?" He asked. "Seemingly your past life is full of betrayal huh?"

Hearing Kai's statement make Haruki had a cold sweat on her face.

"Chisaki-san, I think your harsh words already enough. Haruki didn't mean it at all to betray me." Sofia said to him.

"It's not harsh words. It just a fact from what I saw. As I said before, I don't want any coward or traitorous person in my group. I don't want all of you to fully obey me. All that I wanted… Is for me to trust each of you. Am I clear?" Kai demanded.

Sofia is stunned hearing it, but she knows that both Aiya and Haruki must be spoken harshly to ensure their loyalty to him, since when following Rui, both of them only followed out of fear.

"Y-Yes Chisaki-sama…" Aiya replied while still bow in fear. "S-Sorry… F-For m-making you unhappy…"

"I-I understand." Haruki said while slightly bow. "I-I promise I won't betray you at all." She promised with cold sweat on her face.

"I see." Kai then turn his attention to Sofia. "Sofia, you did good till' now. However, I expect you to grow stronger than now by practicing hand-to-hand combat since there will be a time when you can't relied on your **Blood Demon Arts**. If you want, I and Rui can train you to adapt to active-battle." He offered.

"All right." Sofia nod before looking at Rui. "I hope your help as well Rui."

Rui glanced at her with a smirk. "However, I won't hold back." He stated.

Sofia smiled hearing it. "In that case, I'll not hold back as well. I'll show that I can become as strong as you."

"Now then." Kai then gather the others attention once more. "I'll explain briefly about the fourth and five liquid. The green-colored one is the one that allow you to using **Blood Demon Arts**. I'll correcting what I've said before. Aiya and Haruki, your **Blood Demon Arts** are gone, because when I disassemble your cells, I notice Rui cells in it."

Haruki then gather her courage to speak. "Y-yes. I-it was him who gave us the ability to use it in the first place…"

"Let me explain. Basically, what I did when I recruit them is make them ingest my blood to enchant their ability, giving them string-based **Blood Demon Arts** like me and altering their appearance to resembles me." Rui said.

"Then that means-"

"No need to worry. Losing your **Blood Demon Arts** mean you must try other things to defend yourself." Kai assured before picking up the last liquid. "This purple one represents the vulnerability to the poison that Shinobu called **Wisteria Flower Poison**. I removed this as well so be glad. Now, I will tell a little about my goal. My goal is to making the strongest Yakuza group in Japan. First, we will gather some powerful Oni or humans to our group. Then, we can began to think what good that our Yakuza can be in this Taisho Era, because if you know, on the outside of Japan, countries in Europe is heating up, there'll be a big war that impacted the whole world: The World War One."

"World War?" Rui confused by the meaning. Does that mean that the entire countries in the world will go to war with one another?

"I knew it." Sofia look down while clenching her fists. "Humanity nature is always the same: Creatures filled with greed. Makes the sin of Oni even Muzan himself pale in comparison."

"However, throw that away for now." Kai dismissed the topic. "Because, if Muzan's still alive, we can't do our work properly. So before we can decided what our Yakuza group will be, Our goal is one at this point: Crush Muzan Kibutsuji and steals his pawn as much as possible. Did I make it clear till' now?"

All of the participants nodded.

"Good. All of you can dismiss for now. Tomorrow I'll train Haruki and Aiya and Rui will train Sofia." Kai later raise his hand, signaling that the meeting is over.

After that, all the participants of the meeting is walking out from the main room, leaving Kai in his thought to formulate a plan so good, so evil, so diabolical to bring the King of Oni to his knees. "Now I must research how good his ability in playing his chess right?"

* * *

"I-I can't believe that Kai-sama is that terrifying!" Aiya said to Haruki while still shaking in fear because of what Kai said on the meeting. Currently, she and Haruki are walking through the different corridor than Sofia, since the latter had something to talk about with Rui.

"However, I can't help but think what he said is right. That's why he doesn't treat Sofia, Rui, and those sisters Demon Slayers harshly because they already got his trust." Haruki noted. "Think again. Among all of us, only we that rarely talks with him. How could we can easily gain his trust? Moreover, his eyes… I can see it everywhere. The eyes that deem us as useless."

"B-But if what he said is true… Then we must train to become stronger than we are now." Aiya stated. "A-although I-I don't know how…"

"I also don't know. Don't ask me okay!" Haruki replied in frustration as she walks away, leaving Aiya behind. 'Hmph. That man… He maybe not as fearful as the old Rui, but his deduction is dangerous. Did it worthed… If I betray him?' She thought. 'No. Sofia keep trusting me even though I betray her. How could I think such a thing!'

* * *

Meanwhile on Rui and Sofia side, the two of them are currently talking something different. It is about Kai's plan to recruit other Oni. Surely, they are worried because since other Oni is unpredictable, they may be hard to convinced to abandon their loyalty to Muzan and join them.

But, if Rui can, why they don't think that some of the Oni can be convinced to betray Muzan as well?

"I still worried about Kai-san decision. Even though he already told me previously." Rui expresses his worry. "Many of them already submitted to their instinct or extremely loyal to Muzan-sama. In my mind, I had no knowledge since I'm too focused at my goal."

"I want to help too search as well but except for you, I've never seen other members of the Twelve Demon Moons, moreover Muzan himself." Sofia also expressing her worries. "I just hoped Chisaki-san is prepare for what is to come." Sofia suddenly widen her eyes.

Rui seems noticed this. "What's wrong nee-san?" He asked.

"This feelings…" Sofia uttered. "Kanae is in trouble! My rosary that I gave her is connected to me because I put my blood on it. It can tell if the one that bring it around is in danger."

"Are you sure? She's a Pillar. If she's in danger, only Muzan-sama or the Upper Moons that can do so." Rui stated.

"I'm sure. In any case, I must go to where Kanae is!" Sofia said while turn back to Kai's room. "I'll talk to Chisaki-san for this."

"Wait." Rui stopped her, but she already walk toward Kai's chamber.

* * *

Back to Kyoto, Shinobu currently is staying in Saito's personal room that is being ready by Eiji. He's seen smoking while sitting on his desk. Shinobu herself is sitting on the chair that faces with the desk.

After finish with his smoking, Saito later look at Shinobu while had his hand rest on the desk. "Now then, what the topic about the Juppongatana that you wish to know?" He asked.

"Everything." Shinobu replied.

Saito narrowed his eyes. "The basic that you must know about Juppongatana, is they're a special unit of a terrorists groups that lead by Makoto Shishio. Before you asking who's he, he's one of the hitokiri that allied with the Isshin Shishi, known as the successor of Hitokiri Battousai after the real one step down."

"Hitokiri Battousai?" Shinobu said in confusion with the title before something is ringed on her head. "Did you mean that infamous hitokiri during the Bakumatsu?"

"Yes. He's my rival in fact. During my time as Shinsengumi, I fought against him many times, but always end in a draw." Saito revealed. "Back to the explanation. Shishio however join the Isshin Shishi for one purpose: To shows his power to the imperialists' government and to satisfy his love for killing. That's why he take the silent assassination job different than the Battousai, making him unknown almost to anyone. Even today, hardly anyone knows about Shishio's ever existed."

"So… The government completely shut all the evidence then?" Shinobu asked while clenching her fist. How could they let a dangerous man like Shishio freely roam at that time?

"However… The government later deems him as dangerous enemy due to many important assassinations that he does, they're afraid that Shishio will use it as a trump card against them to rule over Japan. Therefore, they shut him up or in other words… Killed him on the spot." Saito explain. "However… That killing is surprisingly failed even after being shot on the head and have his entire body burned."

Shinobu later shivered hearing it. "B-B-But… How's that possible? No humans should be able to surviving something like that! Is he an Oni?"

"He's human. Although that injuries leaving him severely handicapped, he still as strong as his prime era. Now I don't know how the details he formed the Juppongatana, but he later gather a vast amount of the fanatics in Kyoto that join him based on the principle that 'The Strong Lives and the Weak Dies'. What he planned is to form that kind of country to repel all the outsiders from Japan. But first, he aims to make this country into chaos by splitting it into two using his knowledge as the assassins in the shadow." Saito continued.

"The Strong Lives and the Weak Dies…." Shinobu uttered. "That kind of thinking was wrong. The strong should be protecting the weak and nurturing them, not letting them just rot and died. That's just-"

"The law of natural selection? True. However if we traced back, that kind of thinking is happen in each of human history. The same happens for Meiji Restoration. When the Shogun becomes weak, its assets then becoming the food for the Imperialists that become stronger. Don't you also think like that Butterfly Girl? Maybe it's hard to admit but in your mission as the Demon Slayer, the weak one dies and the strong one remains am I right?" Saito rhetorically said.

"T-That's true…" Shinobu uttered. Although every inch of her wants to deny that kind of Social Darwinism ideology, the practice is unconsciously happen every time. "But… You sound like you is joining the battle to defeat Shishio…"

"That's true. Although I'm lost and his body condition is what that kills him." Saito admitted his lost, although he cannot denied that his injuries from the previous battles is the factor of his losses.

"Then if Shishio is already dead… What about this reborn Juppongatana? During one of my missions, my sister Kanae is being attacked by one of them. What is their goal exactly? I think as a former Police Inspector, you must know something about them." Shinobu pressed on the most important question.

"The reborn Juppongatana huh?" Saito later lit up his cigarette once again. "It's the remnant of Shishio's old ones. Mysterious and rarely appears on public, their target is like what Shishio wants, take over this country, which I think it's the perfect timing since the current emperor is frail and sickly. Myself tried to investigate it, however rarely finds any bright way." He admitted as he smoke. "But… What they aim currently is to crush the two forces that had the high chances of disturbing their plan."

"Let me guess… Is Demon Slayer Corps and Muzan Kibutsuji right?" Shinobu guesses with venom on her tone when she mention Muzan's name.

"Correct. I think that decision is logical. Firstly, if they want to crush Muzan, I can assume that he disguise himself as a conglomerate or someone that have holds in the politics. You can guess what happens if they're taking over Japan while Muzan still on the loose do you?" Saito asked.

"Muzan will try what he can to eliminate them…"

"That's correct. That's why eliminate him first will be the first logical way. After that, they can target their way to decimate your corps. From what I get, your organization value all humans above all others so there's a high possibility that it will stand up against their rebellion." Saito said. "How many members of the reborn Juppongatana that your sister met?"

"Only… One… His name is Arata Eiji. He's Eiji-jiisan son and my childhood friend." Shinobu replied. "He's strong. He even managed to injuring my sister, who is a Flower Pillar easily."

Saito slightly widen his eyes. "I see. Eiji said that his home also attacked by an Oni, with no traces of Arata on there. I can presume he's being saved by the boss of reborn Juppongatana and ask to join him or her."

"You mean…"

"Yes. His wife is dead and this estate belongs to him alone." Saito said.

"Eiji-jiisan… He never told the Demon Slayer Corps about this…" Shinobu said. "If only we know… We surely come and save his wife…"

Saito then sip his cigarette before breath it out. "This starting to get out of the topic. Since you already known about Juppongatana… You don't want to meet one of their members?"

"You mean… A former Juppongatana is here?"

"One of them exactly." Saito revealed as the door to his room is being opened. Revealing Cho with Aoshi on his side.

'That old man…' Shinobu immediately recognize Aoshi. 'He's the one that defeated Lower Moon Three!'

Aoshi then look at Shinobu. "Ah… You're the Demon Slayer brat on that time." He recognized.

"So you already meet this Butterfly Girl Aoshi Shimonori?" Saito asked with interest.

Aoshi nod.

"Hello again girly. It seems you manage to convince the wolf to teach you then?" Cho greeted her.

"While the time is good, I'll introduce them. The man with many katana on his back is Sword-Hunter Cho. He's former member of the Juppongatana." Saito introduced Cho.

"He's Shishio's former allies?" Shinobu become wary. "Then why's he freely roam?"

"A secret agreement." Cho said to Shinobu. "The Meiji Government agreed to pardon me of all my crimes if I become their assets of maintaining this peace."

"Although I was the one that ask him to become my underling." Saito jokingly said.

"C'mon!"

"Then I'll introduce the other one." Saito said. "He's the former okashira of now disbanded group of ninja called Oniwabanshu. Master of kodachi, Aoshi Shinomori."

"Master… Of kodachi?" Shinobu uttered before she remember something. "Then how'd you can kill an Oni? No matter how skill you are, you must use a **Nichirin Steel** to kill one."

Saito then close his eyes while smirking. "Fool. **Nichirin Steel **are easy to get. We have our own ways to get it." He explained. "Then Shinomori, I bet you didn't come here just to visit me right? Since you say you're going back home tonight."

Aoshi nod.

"Let me explain that." Cho take over the conversation. "The truth is, I've got this message from Soujiro, who's on the train toward Kyoto. He said that he seen two female wearing black outfit and strange haori, as well two katana that being hidden by a fabric." His right index finger then gesture to Shinobu. "I guess both of them are Demon Slayers, just like her."

'Wait a minute!? Two women, that means-' Shinobu immediately know who's the one that Cho was talking about.

"Oh? So the Butterfly Girl sister and her friend had paid a visit to here huh?" Saito mused to himself before smirk. "If that so, let's pay them a warm welcome of a swordsman shall we? Inform Soujiro as well about this."

Cho merely nod.

"Wait a minute! How'd my sister know I'm here at the first place!?" Shinobu raise her voice.

"With this." Saito later show the same newspaper that Aoi give to Kanae. "I specifically write it to attract the attention of certain people, with the bet that civilians won't believe anything about a rebellion, just a normal criminal case of Yakuza. Seemingly I play my bait right."

"You… You bait my sister to go here!" Shinobu suddenly shifted to anger. "If anything happens to my sister I'll-"

"I plan this not because a reckless act, but a test." Saito defending his act.

"A… Test?"

"Correct. I already read another reason that makes you unable to become stronger besides your weak body." Saito said. "Your mentality. You're always jealous and think yourself weaker than your cohorts in your organization. That means, you always thought yourself weaker than your older sister."

"I-I never-"

"So what I observe when you fought was right." Aoshi joined the talk. "I can say that you can become stronger than now. However, you inferiority complex is on the way. A true sword-user must never had that kind of feelings. If you do, I advise you throw your sword away." Aoshi said with venom on his voice. "This is a great opportunity. Break the shackles that said you're weaker than your sister by beating her in straight combat."

"But I can never direct my katana to my sister! The reason I do this in the first place is to protecting her! There's no way I can do that kind of thing! It also conflicted with the code of my organization!" Shinobu argued.

"Then what will you choose then? At night, your sister surely arrived with her partner in Kyoto. In addition, you only have few hours left to make decision. Break the shackles that bind your progress… Or keep it?" Saito demanded an answer.

"I-"

* * *

Meanwhile at evening, Kanae and Mitsuri are finally arrived at Kyoto train station. They finally sigh in relief after long hours of travelling.

"Wheew. That's was long and expensive! As I expected of a train!" Mitsuri hummed.

"Now what we must do is to search for the police station where Shinobu being held." Kanae said. "However since we arrive this late, maybe we should look for a cottage first."

"And don't forget Kanae-chan! After this is over, I can't wait to taste the delicacy of Kyoto! Aaaah! I only hope Iguro-san is here to accompany us!" Mitsuri said enthusiastically.

Kanae later had a sweat-drop. "If you're eating at one of the restaurant in here, I'm pretty sure they'll out of stock." She jokingly said. Since Mitsuri had body eight times the strength of a normal human, she needs huge amount of food to keep it at its prime. Luckily, Demon Slayer Corps Pillars salaries are unlimited so she usually spend it to eat.

* * *

Both of them later exiting the station to the road that faces the buildings that starting to show Western Influence on it.

"Ah! I've finally found you! Kanae!"

Kanae widen her eyes and look to the right, seeing that Sofia is running approaching her. She's not wearing her usual white outfit, but wearing a flower-pattern kimono with white cape to cover her face.

"Sofia! What're you doing here?" Kanae asked in disbelieved. Why'd she come all this way from Natagumo Mountain to here?

However Mitsuri immediately reaches for her **Nichirin katana**. "You're Oni are you not!? Why'd you randomly appears!?"

Seeing Mitsuri, Sofia expression then turn neutral. "A Demon Slayer… From what I assume a Pillar huh? Another one who thought their mind always the right one." She stated.

"Even if you look like a cute lady I won't forgive you for killing innocent humans!" Mitsuri countered.

"Both of you stopped it!" Kanae quickly stands between the two with both of her arm open, blocking the advance.

"Kanae-chan what're you doing!? That thing is an Oni! If you keep doing this, that is against our code!" Mitsuri said.

Kanae then closed her eyes, stating her opinion while yelling. "Not all of the Oni wanted to eat humans Mitsuri!" She yelled.

"Kanae…" Sofia uttered in disbelieved. Even in front of her fellow Pillars, Kanae is true to her dream.

"Kanae-chan! Please get out of the way! What she done for eating humans is unforgivable!" Mitsuri reasoned. "Let's go slay her together!"

Kanae now not know how to reply that. All of Mitsuri's words are true. But she then remembering something.

"If that so… Then killing all of us is what you're called pity? How about the others Oni who want to atone for their sins? To reach a dream, someone must take a risk for it to be come true. All humans do the same, even betraying the one that trust them."

"It's not like I said you shall forgive the sin they've committed, but it all based on your heart. Do something what you think is right. Don't ever being influenced by others if you want to chase your dream to become reality."

Sofia and Kai word suddenly ringing once more inside her head. She then yelled. "I dream of a world where Oni and human can understand each other! For that, I don't care even if I hate by many people! Even by other Demon Slayers!" She finally voiced her dream bluntly.

Hearing it make Mitsuri comically shocked. "Kanae-chan…"

"Mitsuri please. Among all the other Pillars besides me, you're the one that having the kindest heart. Please… I know what I did was wrong! However… I still dedicated myself as the current Flower Pillar! So… Please hear me and Sofia out!"

"Sofia…" Mitsuri not expecting that an Oni is having a name, plus a good one. She's now in dilemma but started to seeing that Kanae is speaking the truth. 'Did what Kanae-chan really speaks the truth… But this is against the code of Demon Slayer Corps. But at the same time… Although hard to admit, this Oni had no malice on her… What shall I do?' Mitsuri thought hesitantly for a moment before lowering her stance and look at Kanae. "O-Okay… I'll hear you out Kanae-chan…"

"Thank you Mitsuri." Kanae thanked her fellow Pillars. "But how about we search for a restaurant right now?"

* * *

"EEEEEHHHHHH!? You mean that Sofia-chan being turn into an Oni just because a pity comment!?" Mitsuri said in comical shock as she's eating numerous tofu in one of the restaurant in Kyoto. The time already showed night and numerous beautiful lights from the lamp around the city.

"She surely eats a lot." Sofia noted as she's eating her food.

"It can't be helped. Mitsuri's body had a constitution unlike normal humans." Kanae said while smiling.

Mitsuri then put her bowl on the table and bowed to Sofia making her head hit the table. "I APOLOGIZE! IT'S HARD TO BELIEVE THERE'S A GOOD ONI OUT THERE!?" She said.

"Uuuuh…." Sofia unable to reply.

"That reminds me Sofia. Why'd you go to here at the first place?" Kanae asked.

"Using the rosary that I gave you." She replied.

"Rosary? You mean this necklace?" Kanae then showed the rosary that she keep on her uniform pocket.

"That Rosary is connected because I pour my blood on it. It reacted because this city… You'll enter uneasy situation." Sofia explained.

"I see. And the reason your appearance change this much-"

"Chisaki-san at last manages to separate each components of Muzan's cell that bind us. Thanks to it, we now able to move under the sun, eating normal food, and make our appearance almost resemble our human form." Sofia explaining Kai's success on separating the components of Muzan's cell. "Currently, he is searching for a plan to lure Muzan out into the open."

"I see. So he did it." Kanae said in relief.

"Wait it minute! Did you just said Muzan Kibutsuji's name!? And Who's this Chisaki-san exactly!?" Mitsuri clearly not understand the conversation at all.

Kanae sighed. Seemingly, she must tell about it. "Mitsuri, I'll tell you about something. But can you promise not to tell this to anyone even Oyakata-sama?"

"But why'd I mustn't tell Oyakata-sama about this!? This Chisaki-san can become our great allies!" Mitsuri reasoned.

"Just don't tell him and the others." Kanae harden the condition before finally speaking. "The truth is… Chisaki is the one that saved my life. You see, I was actually going to die after battling Upper Moon Two if not because of Chisaki. But in return, he asked me and Shinobu help to assist him in rebuilding his Yakuza."

"Wait a minute!? He's a Yakuza!"

"Yes. All of his previous members including the boss have being slaughtered by Oni. Since then, he want to restore his Yakuza by searching various comrades." Kanae said.

"And… He recruiting Oni!? That's not lovely!" Mitsuri hummed.

* * *

Meanwhile outside the restaurant, a middle-age man around his early 50s is look at it with a smile. He is wearing a white suit below a light blue haori. He also wear a white zori and carries a katana that being obscured by a fabric.

"So this is where they go for night? Its lucky that Sawagejo-san send me the message to somehow invite them to Eiji's mansion." He mumbled. "Now what shall I do?" He then entering the restaurant.

One of the waiters welcoming him. "Hello Mister. Can I help you?" She asked.

"Ah. Can I order one portion of Dango please?" He kindly ordered.

"Yes. You can wait on the chair number seven over there." The waiter kindly gestured.

"Thanks." The man later walking to the chair that unexpectedly close to Kanae, Mitsuri, and Sofia. He then slowly sits, patiently waiting for his order. He then secretly glanced to the three women. "Ah. So they're here. Now what shall I do so they will follow me to Eiji's Estate?" He then thought for a moment before an idea is formed on his head. "I shall use that maybe."

* * *

"I know that's sounds crazy but if he had that kind of knowledge of anatomy that even surpassed the likes of me and Shinobu, there's a reason he think optimistic." Kanae reasoned.

"But… Why the Oni he want to recruit is the Upper Moons! Is like asking Muzan himself to join his band of Yakuza!?" Mitsuri argued.

"I know he sounds fool." Sofia then talked. "But… He already have a plan to dethrone Muzan once and for all."

"A plan?"

"Hello there girls." The man later greets them. "Sorry for interrupting your conversation. I met the two of you last time on the train remember? And who's the other one?"

"You're that man… Um, Soujiro-san am I right?" Mitsuri tried to remember.

"That's right! As I expected, you're the cute girl that saved me from tripped on the train." The man now known as Soujiro thanked Mitsuri. "Sorry for eavesdropping, but I heard on the train that the other girl is looking for a young woman that goes against the law in Kyoto right? Well, I actually know the location where she's being held."

Hearing this information immediately bring a new hope on Kanae's heart. The Flower Pillar immediately turn her attention to Soujiro. "You know!? Tell me where it is Soujiro-san!?"

"Okay okay just relax." Soujiro smiled while raise his hand. "I actually want to go there as well to meet a certain friend, I'll accompany you to there."

* * *

After that, the four of them later walk together on the streets toward Eiji's Mansion. Soujiro hummed happily along the way, knowing that his plan to lure them out is partially successful.

However, Sofia is feeling something off. "Kanae, Demon Slayer Love Pillar. Please be wary a little. I don't know why but I having bad feeling about this."

Kanae nod while look at Soujiro's back. "Okay." She understood. 'But still… I can't feel nothing from Soujiro-san. He's like not having any emotion at all. I can't predict all of his actions.'

"Don't be like that Sofia-chan! Soujiro-san is a good person!" Mitsuri said.

"Well here we are." Soujiro announced as they're arrived in the front gate of Eiji's Mansion. He then called the security that guard behind the front gate. "Excuse me security-san. Can you please tell Mishima Eiji-san that I already come?" He kindly said.

"Um… I suspect you're Soujiro Seta-san right? I'll open the gate. And who's this three girl?" The security asked.

"Ah. They just want to see a prisoner in here!" Soujiro replied.

'Wait a minute! That name… Eiji-jiisan is live in here!' Kanae thought when Eiji's full name is being speak. 'That mean I must telling him about Arata right away!'

* * *

Meanwhile on the upper floor of the mansion, Eiji is seen look the event on the front gate. "They're coming." He said to Saito, Cho, and Aoshi which all bring their respective weapons.

"I see. Soujiro surely doing his job." Saito compliment. "Then Butterfly Girl, I hope you already make your decision." He gestured to Shinobu, which now wearing her Demon Slayer Uniform and have her sister **Nichirin katana**.

"I-I'm ready." Shinobu replied. "I decided… That I must break the shackles that keep binding me till this day."

"Good answer." Saito replied with a smirk. "Let's greet them on below then."

"Shinobu." Eiji called. "No need to worry. I promise that your sister will not be punished nor that me and the others will injure her and the others heavily."

"I understand." Shinobu replied with a smile. "Thank you so much Eiji-jiisan."

* * *

Meanwhile, Soujiro, Kanae, Mitsuri, and Sofia finally arrived at the front door of the Eiji's mansion.

"So we're arrived." Soujiro said. "At right time that is."

'His aura changed!' Sofia noted. "Kanae, Love Pillar, be care-"

Sofia unable to finish her warning as Soujiro immediately appear behind her and put his katana around her neck.

"What the!?" Mitsuri is in shock seeing his speed.

'That move is like Arata… But he's faster!' Kanae thought in surprise.

"Ara, you figured it out I see." Soujiro said. "As I expected of being that lived for many years."

"You know about Oni!?" Kanae asked in high tone. She then put her hand on her **Nichirin katana**. "Who are you exactly!?"

"Aah. Your tone turn to angry now girl." Soujiro said with his usual tone. "No need to worry. We'll meet again inside the estate." Soujiro stated as he suddenly disappeared and the front door to the estate is being destroyed. Kanae and Mitsuri look to the inside of the mansion that is representing Eiji's wealth as the police officer, but when they saw to the inside, Soujiro that held Sofia is nowhere to be seen.

"He's gone! I can't believe Soujiro-san is evil!?" Mitsuri comically roaring her frustration. "And furthermore, we're trust him easily!"

"In any case, we must chase him. Despite his speed, he probably hides on one room inside the house!" Kanae said as both of them running to the inside of the estate.

Suddenly, an elongated katana is racing toward them with amazing speed. Mitsuri manage to avoid it acrobatically because of her flexibility, but Kanae only managed to do that in a nick of time, grazing her right shoulder.

"Kanae-chan!" Mitsuri yelled in worry as she's still in mid-air. The strange however suddenly turn to the air and grazing Mitsuri's back as well. "AAH!"

"Mitsuri!" Kanae yelled.

From the ladder that leads to the second floor, Cho is seen walk down with grin on his face. "It's useless. This space is narrow thus avoiding my **Hakujin no Tachi** is impossible." He warned. "But I compliment that you only escape with a scratch."

"Ugh." Kanae grunted while holding her injured right shoulder. "W-Who are you?" She asked.

"Oh. Since you have enough courtesy, I'm gladly introduce myself." Cho later swing **Hakujin no Tachi** so it return close to him. "Sword-Hunter Cho. Better remember it clearly." He said.

"Sword-Hunter… Cho?"

"Kanae-chan!" Mitsuri then approach her. "Are you all right!?"

"I'm fine. His katana is only scratch my right shoulder." Kanae said. "In any case, that katana of his is dangerous. It can move freely in this narrowed room. But… I have one conclusion why'd this man and Soujiro-san have a katana. That means they're police, a high-rank maybe."

"Correct young girl. As I expected of that Butterfly Girl older sister." Cho praised Kanae.

"Butterfly Girl? You mean Shinobu!? Where's She!?" Kanae pressed on as she unsheathed her **Nichirin katana**.

"She's definitely all right no need to worry." Cho then swing his **Hakujin no Tachi **once again. "But if you want to meet him, you shall get through me first!"

However, another flexible katana, but shorter in comparison to Cho's, is parrying the strike that aim at Kanae.

"Hm?" Cho is surprised by this new development. "Ah… So your katana had the same density and flexibility as the **Hakujin no Tachi** huh?"

Mitsuri is seen standing protectively in front of Kanae, wielding her special **Nichirin katana** from the sheath. "Kanae-chan, you better go ahead! I will somehow hold off against this loveless police!"

"Mitsuri…" Kanae didn't believe that Mitsuri dared to defy against Demon Slayer's code to not bring out their **Nichirin katana** in front of humans. "But, the code-"

"Forget about that now! We can't win against him if we keep stick to the code at the situation like this! This police seemingly a powerful swordsman." Mitsuri yelled. "Now go ahead!"

"Like I'll let you!" Cho swing his **Hakujin no Tachi** once again with the intention to harm Kanae.

'**Breath of Love First Form: Shivers of First Love!**' Mitsuri later dash forward with a series of slash to parrying each part of Cho's **Hakujin no Tachi**. "I won't let you hold off both of us in here!? That's so unfair!"

"None is unfair. As I love is only best quality katana." Cho then unsheathed a katana from his back to parrying Mitsuri's attack. "I'll take that whip-like katana of yours!"

"Try it if you can old man!"

Seeing the chance, Kanae run forward and then jump high, passing Mitsuri and Cho.

"Tch." Cho grunted seeing Kanae managed to pass him and now he must force to fight Mitsuri. 'W-What's this strength!? I feel my muscles tensed parrying the katana of this woman!' Cho later had no other choice but breaking the parried and take a step back. "That's amazing muscle you got there. Completely opposite of your body."

"Thank you so much for the compliment!" Mitsuri thanked Cho before turn serious once again. "But for what reason you and all the Polices in Kyoto doing this?"

"It is obvious? That Butterfly Girl forbids the law and therefore it's natural that she's being imprisoned right?" Cho asked.

"That's maybe true but she did that for a reason like you police. Please just listen to us and we can explain this!" Mitsuri reasoned.

"Aah. Those will too boring. Because I've heard that your Demon Slayer Corps have this Pillars that said are the strongest swordsman." Cho later swing again his **Hakujin no Tachi** forward. It zigzags rapidly. "Explain to me with your strength instead!"

Mitsuri managed to avoid it to the right side. However, Cho is smirking.

"Got you!" Suddenly, the extremely long and thin katana that was forged by Shakku Arai is change direction upward before it suddenly descend and managed to slash Mitsuri's left shoulder with quick precision. "C'mon Sakura Mochi Girl! Show to me all of your strength!"

"Ah!" Mitsuri yelped while holding her injured left shoulder. 'Don't worry Kanae-chan! After I beat him, I'll catch up!'

* * *

On Kanae's side, she managed to reach the second floor and opening a door to the large hall for a house. In the middle of it, Aoshi is seen standing, seemingly expecting her arrival.

"I've been waiting for you, Kanae Kochou of the Flower Pillar." Aoshi greets her neutrally with his usual calm face.

'There's more than one polices in this house!' Kanae thought in surprise as she walked forward. "Please just let me go police-san. I had no intention to harm any of you. I just come here to ask my younger sister to be spared."

Aoshi didn't reply. "Your plea falls into deaf ear. I'm not a police." He said. "However now I can see. Why'd that girl… Shinobu Kocho can't become stronger." He then unsheathed one of his kodachi. "You're the reason."

Kanae didn't like the way of this conversation. "What do you mean?"

"She can't become stronger because she looks up to you, which unconsciously be her shackles from becoming stronger." Aoshi stated.

"What?" Kanae is shocked before shaking her head and feeling insult by Aoshi dares to guessing about her and Shinobu. "You know nothing about both of us! Please let me through!"

"Then I'll humor you.,, Before she prepared." Aoshi then dash forward and doing a downward one-hand slash with his kodachi, with Kanae block it. The clashes then happen several times before the two keep their distances. Aoshi is prove not losing his agility despite his age that already close to sixty.

'This man, he can keep up with me casually. Who's he exactly?' Kanae thought.

'Hmm… I've heard that the Demon Slayers using some kind of **Breathing Techniques** to strengthen their muscles and all of their stats. However, she's refrain from using it yet manage to even against me who also holding back.' Aoshi thought in surprise. "In that case… I'll be serious now." Aoshi then dash forward again and slash sideways which Kanae managed to block. However, that was just a diversion to make the former leader of the Oniwabanshu delivering a devastating kick on her stomach with his left leg, followed by a punch on her face, making the Flower Pillar thrown backward but manage to stabilized herself.

"So… You're the user of Kenpo as well?" Kanae didn't expect it until she finally spat blood on the floor. 'Ugh! His attack had an aftershock effect!?'

"Stand. Kanae Kocho. Let me advice one thing. You free not to kill me. However, if you keep holding back like this, don't perceive it as my fault when I'm gonna kill you and your friend." Aoshi stated harshly.

**Notes:**

**And there goes the Chapter 9! I'm sorry it still not include Kanae vs Shinobu because it's still an opening fight. Will Kanae and Mitsuri still must fight other three or not? Just wait for the next chapter.**

**In this story, I already plan to make Rurouni Kenshin characters still had their amazing technique and strength despite their age already old. As for Kai plan, it still be a long way.**

**By the way, this is the age for the Rurouni Kenshin characters that appear on this chapter:**  
**-Hajime Saito = 68**  
**-Aoshi Shinomori = 59**  
**-Cho Sawagejo = 53**  
**-Soujiro Seta = 51**  
**-Eiji Mishima = 46**

**See you in the next update! Be safe from currently spreading Covid-19. Decrease all activities on the outside, frequently wash your hands and keep your health in check to stop the spreading of the viruses. I hope all of you save from the viruses.**


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